They're good. Scavengers, mostly. As mentioned, there are a few rare kinds that can be bad, but generally, our run-of-the-mills pink/blue guys are good.
I figure, if someone is marketing them (and has managed to stay in business as long as these guys:
www.ipsf.com), I'll keep mine.
(That was a blast from the past... I haven't ordered from them in, golly, 5 years? Longer? Good biodiversity company, though. I could barely remember their name)