I’ve heard nice things about WebOS, but, well, I honestly haven’t given it a fair shot. There just aren’t enough apps for me to use it on a daily basis. I wasn’t even interested in using the thing until I decided to put Android on it one day. But after I managed to install Android (alongside WebOS! even though I don’t use it…) I use it almost daily.
I’ve been running versions of Ice Cream Sandwich on it. There are apps that just look and feel better on a tablet interface instead of a phone, and apps that only work on Ice Cream Sandwich as opposed to previous versions of Android.
Currently, I’m using OaT’s 0829 build. It’s basically a stripped-down version of CyanogenMod 9. However, OaT’s builds are not currently available. CM9 is an excellent ROM as well, though. The nightlies (now weeklies) are very stable, and few changes are being made at this point. The Alphas tend to have wifi problems, so I haven’t used them for awhile.
Finally, note that no Touchpad ROM has a working camera, though work on it is ongoing. But even without a camera, the Touchpad is still a great Android tablet, thanks to some dedicated developers.