I own a [url=http://www.thomann.de/de/harley_benton_pb_50_sb_vintage_series.htm?offid=1&affid=1&subid=307763&subid2=Harley+Benton+PB-50+SB+Vintage+Series&origin=boost&gclid=CIS-tNuhlcICFcKPMgodox0ABw]PB-50[/url] and I must say it's a fine bass. Fit and finish are more than just acceptable, no sharp edges at the frets, it plays well, and sound good. The only flaw I found when I first laid a hand on it was a slightly tilted pickup: the screws were not set in at a right angle - easy to fix.
Another downside - especially for a "serious gigging musician" - is the weight: 4295 Gramms is not brutal, but probably more than what you want to hang around your neck during a 2 hour show.
Anyway, if I was in the market for a 5-string P, I'd rather go for the Squier VM, because IMO it just looks better. The build quality is on the same level.