I've bought my last two basses sight unseen online.
The first was a Squier Jazz from Andertons, the first one they sent me was set up okay, but the back pickup broke within a week, I was able to exchange it no problems and the next one they sent me was technically faultless, although I did set it up to my preferences.
Then , back in January, I got a Mexican Precision Special from Guitar Guitar. I was really impressed with the set up on that one, the intonation was spot on and the action, which I'd describe as medium low, was perfect for me.
My next buy will almost certainly be a Sire V7 fretless and I have absolutely no qualms about ordering one online.