Which is your twitter app of choice? I played around with them both and for me Plume seems to offer more. I can at least look at photos which i cannot in Tweetcast. Plume also has a widget which Tweetcomb do not.
I use plume(free version) my self. I like plume's widget and it's three panel view. And so far I never had any sort of techical issues unless it was caused by twitter itself.
"Be as smart as you can, but remember that it is always better to be wise than to be smart. Alan Alda"
Neither Tweet caster HD is more feature rich right now for Honeycomb try it