I think one of the real reasons that I haven't liked R is the default interface blows (sucks, whatever). I just discovered the Eclipse plugin StatET. This things rules. Contextual help, completion, object browser, data browser, etc. There is even a debugger that I haven't tried yet. Thank you WalWare!
Still not going to use R for matrix manipulation (a UI can't fix slow), but I'm going to be using R a lot more.