I've posted this on the forum before, but here's a gig I recorded last year with the XR18:
I've never had problems with the USB recording; think I've done up to 14 channels into Logic on a MacBook Pro and can record for hours without issues. As long as the gains are right everything's sweet. I really like the preamp sound; way better than the price would suggest. Would recommend an external hard drive though (I use a
Lacie Rugged which works great)
I had increasing dropouts with the built in wifi in busy gigs (as far as I can tell due to more mobile phones than anything else) but have started using an external router and no problems since.
Once you get used to it, the app is truly remarkable; so many features! There's really nothing I've wanted to do with it that I can't. Even multiband compression on the output mix, which sounds great. There have been a couple of bugs, and I once had to do a hard reset before a gig that was a real pain in the arse, and currently have lost the main output meter display, but not bothering me immensely.
I've been close to upgrading to the X32 rack several times, but really not found an excuse to yet!