I started on a 4-string back in 1985; in my early formative years most commercially-available (read: cheap enough I could afford them) 5-string basses s-u-c-k-e-d hard. It didn't help that most bass amps and speakers had trouble handling those lower notes without distortion. The first couple of fivers I owned I didn't keep long.
Ultimately I did the whole B-E-A-D tuning on one of my fours, and the pickup system on that bass handled it way better than any of the cheaper fives through my rig.
Years later I finally decided to try "the mighty six" and never looked back. I have owned a couple of fives since, but usually only for a couple of weeks - I don't even look at them these days when I am bass shopping. It's not snobbery - if I don't have the high C, I kinda tend to miss it with the stuff I play.
From the perspective of an older guy (almost 50), I use the low B for a few things: first, as pointed out, it makes a dandy thumbrest, which is how I use it a lot of the time; I will use it as an accent for particular 'hits' in a song for additional punch; I'll use it in the bass line as played if the line calls for it; and finally, I'll use it to extend walking lines/patterns in a song where changing octaves or direction else would sound 'off'.
I won't say there is a "wrong" way to use the low B. I will, however, say that it was always a running joke among myself and my friends that you could usually tell the guy who just got his first five-string, in that he wears out the B string and forgets the others exist for a while.
Maybe the best advice I can give is to just go play music and have a great time, rather than worrying about which string you're playing the music on. As someone pointed out previously, if it sounds good to you you're gonna be just fine.
