Wow. Okay, listening to those clips, I think I may tweak my M/S pair placement on piano. Man, that sounded nice.
It's also official. I hate the sound of spaced pairs. I listened to the small ensemble and only the X/Y sounded natural to me. That said, the most widely spaced omni pair captured the character of the hall much better; the X/Y sounded very dry by comparison. IMHO, they were way too close for X/Y recording.

I would love to have heard it with M/S thrown in for comparison.
Who here thought the vocals were lost in the mix with the slider all the way to the right? The best blend felt like it was about the middle of the slider. Of course, this was with laptop speakers, so it may be just that the mic and/or singer needs a little EQ to cut through adequately on smaller speakers.
Their room needed work for the speaking voice. The first one was fine. The second one was decent. The third one I started hearing pretty significant early reflections. By the fourth one, it just plain sounded like he was speaking through a cardboard tube.
Nice mics, though, and an amazing site.