Going on 12 years of playing. Practiced everyday for my first 2 years at least 2 to 3 hours (often much more), and never missed a day at the time.
Ashamed to say I don't play but a hour or so every 2 to 3 days now. Family and job make it hard to practice alot or stay motivated. But it's not useless practicing like I used to do (endless hours of the same old shit). Whenever I play now, it's almost always something new and usually challenging (I find I progress faster with less hours when it's quality practice). I dug into my old tapes and I'm finishing up learning Stuart Hamm's "terminal beach". I think I'll do a Wooten song next or try out some new music theory exercises I've been meaning to delve into.
I'd say, however, for a bassist of under 5 years experience, to put in as many hours as possible. Ya gotta get those techniques developed (just make sure there's no technical flaws that will come back to haunt you). That's my 2 cents (or a dollar and a half).