I have the Rubicon II. It'll cover your basic analog needs. It has a tremendous amount of range with a ridiculous number of octaves available. Being able to switch octaves quickly is a big plus in my book compared to the Tip Top Z3000 where you have to manually sweep it. It also servers as a complex LFO, which is an undervalued feature considering the modulation possibilities.
The Rubicon is only as good as the modulation you pass through it as with any oscillator. Lately, my philosophy is to start patching modulation ideas first and foremost then connecting the modulations to different aspects of VCOs, filters etc.
Having a nice collection of oscillators and a wimpy amount of modulation is no bueno and not a lot of fun. I'd definitely research Lugia's sage advice. Honestly, I think I almost troll these forums to get a reply out of him. :)