I tried Froyo and CM7 and couldn't get used to the soft keys. with CM7 2 months ago i wasn't able to connect to my office's wireless network.
I switched over to Deeper-Blue's V4 honeycomb, and the only issue i honestly had for my use of the tablet was no calendar support and having to unmount the SD card in order to install some apps.
I ended up buying Touchdown Exchange to take care of the calendar/email for my business, the wireless worked at my office, and i could play angry birds on a bigger screen as well as reading my kindle app.
I've swapped over to MadCat's new version of honeycomb and while somethings aren't completely stable it is working well for what i do with my tablet, and it's compatible with the latest Kindle app.
just my 2 cents.