For my "desktop" rack, I didn't want to get a complex oscillator because I wanted the freedom that individual modules gave me as far as features and routing options.
I've recently been putting together a smaller portable rack and decided to get a complex oscillator as a way to save space. I had considered the Instruo Cs-L, but ended up going with the Cosmotronic Vortex. The Cs-L has some nice modulation routing features, but I felt it was easier to see what was going on with the Vortex. I'm happy with it (though I still prefer individual modules). The only thing I don't like about it is that the tuning knobs are big and close to the FM controls (making it easy to knock the tuning out).