Using Quicken 2010 Premier, migrated from 2007.
In general, with a few days of use behind me, I think I like it. There may be some features I'm seeing that originated in 2008 or 2009 versions, so I can't be sure that all of the changes that I've noticed are from 2010.
I like the new register look, with checkmarks next to items that haven't been reconciled, and the indicators that show things that will impact income tax.
I like the pop-up registers, but there are bugs with using them. You cannot shrink the register windows. You can stretch them, but not shrink them. I have reported this bug to Intuit. If you are not using the new feature you can shrink the window with the register just as before.
With pop-registers Ctrl-M does not work to memorize a payee. With pop-up registers disabled Ctrl-M does work as before. I have reported this bug to Intuit.
If you go to Help > Product and Customer Support and do a Search, it always says "This program cannot display the webpage". If you go to Help > Quicken Support it does work (and brings up a tab in my browser which is nice). I have reported this problem to Intuit.
I was surprised that my customized initial View from Q2007 did not come up after starting Q2010. Going to the "Planning Tab" and selecting "Cash Flow" does recreate my old main screen except it does not show the calendar. I have created a new initial view with four sections: Stay on Top of Monthly Bills; See Where Your Money Goes; Budget; and Calendar. Still seeing if I like this better, but disappointed that the calendar doesn't show any indication of what happens on each day the way the old small calendar did. The new small calendar only shows which days have activity. You can still mouse over days with activity to see what the activity is.
The "Stay on Top of Monthly Bills" section does not let me click on an item does not let me click on an item to indicate that it is paid like I expected. Clicking on an item in that window just lets me change the amount of the bill. I have to click on the Bills tab to indicate that a bill is paid. But there are forward and back arrows at the upper left of the Quicken window that make it easy to go back and forth.
News for investment items opens in a new browser tab (Firefox in my case). That is MUCH better than the old way.
I think Quicken 2010 starts up faster than the older version, and I think the backup may be faster too.
The first online transaction download took a little longer to get started, but subsequent ones seem fast.
I like the "Tags" that can be entered with each transaction or on each line if a transaction is split. I think that is going to be useful and is certainly much easier and more intuitive than "Classes" were in the older versions. (And I've used a LOT of older versions.)
I'm sure I'll learn more and get used to the new look, and I don't mind the new look at all.
Bernie