I disagree that you get an appreciably higher level of reliability with boutique. OK, out of the box you probably do, but I tend to take a cheap instrument and tweak it - tighten down the bolts, redo the soldering, adjust the action, etc. In the end I know the instrument very well. I probably wouldn't have to do much of that with a Sadowsky. Certainly not the tightening and possibly not much adjusting the action.
My latest project bass has been a real learning experience - badly cut nut, a shim where it didn't need one, truss rod not tightened at all out of the box, action a total mess and at this point the D and G strings are practically inaudible compared to the B, E and A when you're in an ensemble. But I honestly believe that I will have a bass that I can confidently take to gigs when I'm done. In fact, if I had to choose between a cheap bass that I've lived with for a while and a brand new boutique bass that I haven't spent much time with to take to a high profile gig, the cheap bass would win.
All that said, this is not a slam on Sadowsky or Lull or Alleva Coppolo or those fine basses that Munji posted. Maintenance is part of the whole process in my life. I'm more confident doing it to cheap basses because, well, it's a cheap bass. On the one hand I wouldn't have popped off the neck and the nut and sanded the fretless fingerboard on a boutique bass - I'd have brought it in to a reputable shop and had it done properly. On the other hand I wouldn't have had to. But I enjoy the tweaking process - making a less expensive instrument as nice as I can. I wouldn't trade my Tokai P-Bass for any boutique bass sight unseen.
KO
I think your response kind of proves my point... I don't have to worry as much about tweaking and maintenance w. my Sadowsky... why? Because it's reliable. The fact that you have to go tweaking and messing around with cheaper basses is proof that they're not as reliable. Perhaps you can tweak them to the extent that they are reliable, but personally, I'd rather pay extra for a well made product, than buy a cheap one that I'd have to put a bunch of physical effort and energy into hopes of bringing up to the level I require. That's just me, though.