Hey Nick, sorry I didn't chime in here earlier...haven't been trolling all the forums here.
I have some samples with the at853Rx as well. One mic'ed right off the stack at a very boomy bar here. I've had no problem with distortion or anything with these mics. The bass response on them is great, IMO. I used to own a pair of the SP at853s, and they just couldn't handle the SPL at a lot of shows.
I haven't listened to your sample. I'll d/l it tonight. But if you'd like some samples with my mics, I can dig up some of the raw recordings and make some mp3s. I don't claim to make great recordings, but it should give you a good feel for what they pick up. Schwilly's samples are much better than mine, though
i can prolly get a pair of the SP cmc-4's to run side-by-side with the at853Rx if you really want. I think a friend of mine has a pair.
J