I would suspect the mics are the issue..... Again another person selling mics that thinks that bass roll off eliminates distortion IT DOES NOT. All it does is reduce the output of bass from the mics.
Yes, I always suspected there was some "distortion paranoia" involved with their product lineup, the way they force feed you the roll-off option. Also deceptive, as there's an option to pay $2 extra for fixed roll-off even though all their battery boxes come this way anyway — no exceptions.
It's funny though, because all the recordings posted on the Giant Squid site sound really thin. I'm not sure how this is supposed to be a selling point?
I don't have the exact specs, but it seems their roll-off filters are set at something like 250 Hz or higher.

Well... My friend is currently living in Europe, so I'm not sure if it's worth it for him to ship the mics that far. I'll point him to this thread, though.
Is he recording loud shows? Those mics are somewhat notorius for not being...uh..of a high quality. If he is recording loud shows, they may simply be not able to handle the high(er) spls.
Yeah, some of the shows were pretty loud.
I had another friend who taped with Giant Squid omnis plus using their standard battery box, and he always got decent results with loud rock shows — only that many of the recordings were lacking bass.
So for this reason, we both advised against this guy getting a battery box from Giant Squid.
Also, the mics were purchased brand new... So that would be pretty lame if they were defective somehow!
Thanks for the replies so far.