In case you didn't hear, there is a war going on out there.  Not *That One*, but a Financial Planning Software War.  You're first thought is probably between Quicken and Microsoft Money, and you're right, they are also competing, but the war I'm talking about is between Quicken Online (QO), and Mint. 

Both of these checkbook products want the business of causal people with minimal financial tracking requirements and both offer enough online visual analysis of your spending tools to help guide many people towards better fiscal living though realization of your current habits and goal planning.  A quick Google of these two will provide you with too much background information regarding their current battle to reign supreme, but I'm focusing today on Quicken Online because in their last big move to surge ahead, they made the product free.

The Good

• If you dread setting up checkbook software, QO may be for you.  The super simple, fairly intuitive, easy to navigate setup and day-to-day usage interfaces take the dread right away.
• Once your accounts are all linked, getting useful information out of your data is a breeze.  Beyond just gleaning stats from the individual account transaction sheets, the QO Home page quickly summarizes upcoming bills, the status of your accounts, how much you have left in your primary checking, your spending outlook for the next week, as well as additional financial goals you can set up and visual charts to aide in better planning.
• Its a web application, which already means you have no data locally to lose in the event of a disaster and you can access your information from just about any internet connected place.  QO looks good in IE, Firefox and Chrome, so you will probably not need to switch browsers to use it.
• Have an iPhone?  "There's an app for that."  QO for your iPhone is also free and makes management of your accounts on the go easy. 
• Theoretically, QO automatically syncs your account transactions in the background (you don't need to be logged on) daily.  I'm a little skeptical, as there are a few accounts that QO always shows as "Yesterday" being the last sync time, no matter what time of the day I log in.  Either way, a click of the Refresh button in any account will refresh the data for that entire financial institution when desired.
• QO "learns" what your transactions are.  You will need to take a few minutes after you first link your accounts to rename the Payee's from whatever cryptic identification they send the bank to something you recognize.  From then on, QO will often auto-replace for you on next update.  Same with Categories, you'll need to double check what QO decided your transaction was and replace with one of their general options or one of your own, but after that it does a nice job of auto-selecting for you.
• Trends.  We all love them when they come in the form of pie charts, and love them even more when someone tells you what all those colors together means.  QO has 'em, and entire page of them, and for the most part, they work well.  We did notice that the more complicated your accounts get, the less likely it is that your returned data is correct right off, but can get closer the more you tinker with things.

The Neutral

Not a show stopper, but a few things really annoyed us when working with the application:

• Clicking on the Accounts tab, our first linked account is always in the "rename" state.  It's pretty much an HTML rendering issue whereby the first input field receives focus, but more than once I've renamed or deleted an account name by accident.
• Only one account can be on your "home page".  If you have perhaps multiple checking accounts, the home page becomes less useful as it only shows the balance of one specific account.
• Manual refreshing can take forever.  Go get a cup of coffee after you click the button as the meaningless progress indicator will be there for a while.
• Does the application ever time you out from non-use?  I had it open in the browser for well over an hour without use, and it didn't seem to mind when I then navigated around.
• Everyone likes to tweak things, the way a program looks, responds, data it shows, what it does for you and when, etc.  QO has a settings section that underwhelms in this department.  For instance, when looking at your transaction sheet, QO drops all digits right of the decimal point.  Your totals are correct, but you don't actually see the exact figures.  Want to change that?  Too bad.

The Bad

You can't use QO without linking to at least one financial institution.  If you don't want to give out your bank login information, too bad, as there are also no "dummy" institutions.  This means that if you want a 100% manual tracking system, you probably should look elsewhere.

You didn't really want to stay logged in during this transaction, did you?  More times than not, when adding a new financial institution, you get all the way to the point of selecting the accounts to link to, and QO logs you out.  In the background, of course, so you only get an error message when you press the Next button to continue the linkage.  You then need to repeat the wizard, which always then seems to keep you logged in.

No import, no export.  Let say you're mid-year and decide to make the switch from whatever method you're currently running to to QO.   You don't want to be greedy, you just want this fiscal year's data to be ported over.  Too bad, you can't.  When you link a new account to QO, it will only download the last 90 days worth of transactions from that institution.  As the program has no import feature, you're additional data is lost.

You've heard of Window's "Blue Screen Of Death", and Vista's "Green Bar Of Death" - add QO "Yellow Triangle Of Death" to the list.  This appears on your Accounts listing whenever QO can't connect to your financial institution.  Don't expect to click it and get much information, as when you do you'll just be taken to that account's transaction sheet where you will see the YTOD again with a generic reason for the issue and a "Please click here for next steps", which will typically lead to an interaction with Tech Support (See "The Really, Really Ugly") 

The Really, Really Ugly

"It is possible that these [Accounts] from [Institution] are not supported by Quicken Online".  Actual quote from Intuit Employee, not tech support, and only in their Online Community Forum.  Sure, you may follow QO's Add Account wizard thru the selection of your know and approved bank, successful logging on to your bank from QO, successful retrieval of accounts available for you to link with, and an otherwise successful linkage - but don't be surprised if that turns out to be the last time QO will be able to speak to all or some of your newly linked accounts.  See YTOD above.

Brace yourself for, and somewhat not too terribly surprising, their off-shore, outsourced tech support.  You'll be sending in many an error report and will always be met with the following:

1. Automated response thanking you for your submission. 
2. Ridiculously generic form letter from whatever tech opts to take a look, which will tell you something along the lines of "[your issue] is likely caused by a problem between your financial institution and the Intuit servers. We have forwarded this issue to our online banking team for resolution"  or  'do this, then this, then that, then this, then get back to us if it still doesn't work'.  The latter tends to have little to do with your reported issue. 
3. If you do decide to get back to them, you will probably get a single response back, again mostly canned, then don't expect to ever have your issue fixed or hear from them again.  This is a very prevalent issue and has a good number of complaints about it posted on Quicken's own Online Community Forum.

Same bank, same account types, two different users.  One user linked and updated without any issue, the other could never get the linkage to work.  No explanation of why, no visible reason for the failures (other than the generic error message and canned tech support emails), just doesn't work.   We saw this actually more than expected. 

The Bottom Line

QO will either work for you right from the start, or it won't.  If after your 10 minute initial setup all accounts link and update as expected, it's a great casual checkbook application with the perks of being available anywhere.  If it doesn't, look somewhere else as you're issues will most likely never be resolved by their "tech support" and there is no point in dealing with the frustration of a checkbook solution that only gives you a partial picture of your money.