I may have been hasty...

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.