I've got three, with one on the way, and I actually like how they sort of "force" my style to change. Quite literally, different styles emerge from my fingertips depending on what I'm playing. With my 6, I get the full range, and feel like there's no limit to what I can do, from rattling the windows to doubling the guitar... Yet I don't slap it like I do my P-bass 4 string, and certainly don't jam along with Jaco or AiC like I do with my fretless 4 string. I think I'll be picking up new basses as the urge hits me, within limits. I don't see a point in having more than two of one kind of bass, a main and backup. But I like to switch things up.