No problem with 2009 here...
I have used Quicken for about 15 years. My most recent version was Quicken 2006. Since they do not support Quicken for more than three years I was forced to buy 2009. Given the bad reviews I was expecting the worst. That conern was not supported by the flawless installation of 2009 I experienced on my PC. Everything went perfectly including the update to version 3.0. I'm not sure why some many poeple had issues. My Quicken data base is very large including banking and investment transactions, etc. I would highly recommend this product however I find it hard to accept Intuit's policy requiring updates every 3 years. 2009 is essentially a cosmetic rework of 2006, nothing significant in terms of new features and functionality. Just a way to provide Intuit with a revenue stream....

Intuit / Quicken products seem to be detriorating in quality every year
I have been a quicken and turbo tax user for the past 10+ years. I currently own quicken 2008 home and business. The product stopped working on 1/1/2009 due to some bug in the software. I have been unable to use quicken since then (without having to do a unwanted workaround which includes changing the system time). Quicken tech support has been aware of this issue and they still haven't provided a fix for this fatal issue.

Based on my experience and reviews on this site, the quality of software from intuit/quicken/turbo tax has been deteriorated.

Do not recommend
If you are an existing Quicken user, here's what you will find with 2009.
1) It is buggy. I'm now running the third release of Q2009 and it still crashes on me regularly. I've never seen Quicken crash and I've been using it for over a decade.
2) Your online banking may stop working. Mine did. Quicken Help suggests deactivating the accounts and reactivating them to get them working again. It worked for me.
3) It's noticeably slower. It's most apparent during a reconciliation where a click on a check takes a full second to accept. Clicking on an existing transaction in the register takes a full second to obtain focus. It was not this way in Q2007.
4) If you use the calculator in the amount field, you now have to press in order to accept the full calculated amount or it will only take the last calculation. A minor irritant, but consistent with almost every transaction I enter.
5) New categories will suddenly appear in your category list. You will need to delete them.
6) Minor changes to the interface. Some are okay, like the new tabs across the top. None are ground breaking. The interfaces that should have been fixed, like manually matching the downloaded banking transactions to the existing transactions in the register, were not touched. Still very poor feedback when doing an Update from your bank accounts. The Account List is very different. I find its new creativity gets in the way of usability. Little, unexplained icons now appear on your register and other parts of the interface.

Overall - a $90 disappointment. I do not recommend this version of Quicken, especially not at this time while it is so buggy. Wait and see how 2010 works out.

Garbage.
The worst ever! I wasted my week off between Christmas and New Years trying to get it to download transactions and to prevent it from crashing. It's now January 3 and it STILL will not work. Problem after problem. I have used the previous Quickens for years (never downloading though) and 2009 just plain does not work. Worse than the wasted money is the wasted time.

Another disappointed long-time Quicken user
Like several other long-time Quicken users I have been very disappointed with the Quicken 2009 release. I upgraded from 2006 which I was very happy with but now I am considering a search for an alternative checkbook management program. Some of the disappointments:

1. The "upgrade" option for existing users turned out to be more expensive than buying as a new user.

2. The Savings Goals feature was dropped from Quicken Deluxe. I found one online poster saying it was in the Premium version but Quicken support didn't even give me that much help.

3. Both the program help and online help are very poor. Quicken's user forums are frequently offline.

4. The Home Inventory feature is a joke. This tool hasn't been updated since the mid-1990's.

I hope these is a financial "Firefox" out there that can save us from these Intuit and Microsoft behemoths.