I never encounter any bugs yet. The latest version solves many of the stock FW's nagging issues plus the all the goodies that comes along with RB.
Themes I tried so far the works well.
Basically, you can try any themes made for a 320x240 screen resolution. That means most iPod classic themes. But not everything works with DX50. Some needs a few tinkering to make it work.
Ah I see! Well that's good to hear that it's running well now, and hopefully we'll have some tweakers to have some themes up and running specifically for the DX50. I haven't been in this thread, but has anyone modded the themes/UI so it works with touch functionality? (Although touch isn't something that concerns all too much - I can easily do without)