I have pair of Big Baby 2's and, though I'll sometimes use a couple of different G-K heads, I mostly use my D-800+. I'm very happy with my sound but, even better, is that my bandmates are very happy with my sound, especially our guitarist/soundman. He'll walk out around the room periodically in our first set to hear our mix and he always tells me that the bass sounds "SOOO fat!". That's the most important thing, how I sound out in the room and, since I rarely go through the PA, my rig is what the crowd hears.
I don't use my amp for any noticeable "coloring", I primarily set it so it sounds good in the room with my bass set flat. Then I can take advantage of the controls on the basses to tweak the tone as needed for different songs. That's what I like about the 12" series - they're pretty transparent so the tone of your bass is what comes through. I know for some that transparency and full range sound is a disadvanatage and, for those, the 10" series is probably a better choice. But I don't think either is wrong, it just depends on what you want.