I'm impressed with the changes to the menu. The previous version (1.3) used the stock Android menu buttons and had all of the settings options under one menu. It looks a lot better than before and it's also better organized. The new in book menu adds a button for the home screen (also new), search, and a slider bar for location in the book. You alos can now see the taskbar across the top of the screen (no need to exit to check the time).
There's only 4 buttons on the menu (down from 6), goto, day/night, settings, and a More option. I won't go into laborious detail but the way the settings menu was restructured shows a serious amount of thought and user testing. The options I wanted to change most often were the most easily accessible, with less used options one step away.
The Home screen I mentioned before is new. I'm not talking about the library; don't worry, it's still there. No, the Home screen is where you'll find find links to the ebookstore and where you'll import ebooks.
That's one of the things they've changed. You don't have to put your titles in /import folder anymore; Aldiko v2.0 can find them anywhere on your device. This is simply awesome. I've had problems with some Android devices because Aldiko expected to find the import folder in a place I couldn't access.
I've probably put more time into this app than it deserves, but I do like it.
As a final note, I think you might want to wait for a more polished version. I'm having some stability issues with the version currently on the market. It's also running rather slow on my Pandigital 9" tablet.On the other hand, they do offer free updates.
P.S. I didn't test library support or ebookstore support. I don't have a library that supports ebooks and Since I always strip DRM from ebooks my rule is to never transfer directly to the ereader.