Well, I'm not using an r-4, but I use my w+mod ua-5 for 4 mic mixes as much as possible. Not sure off hand the exact number of times I have run this but I will list my configs and type of enviroment for the last 5 times.
1. WSP in Memphis this summer, 2nd night (7/29 I believe). Ran a flanking (split 15' pointing at the outside of the stacks) of my Peluso subcards straight into the ua-5. I had a center pair of 414's, DINa hypers >v2>rca input. Of course all of my 4 mic mixes have to be done on the fly so it is a little iffier results than if I could mix in post. My thoughts on the results. Loved it. The hypers brought a more in your face sound but the subcards really opened things up. Was very impresse with the results. This was from the OTS.
2. 7/21/06 - South Cumberland Orchestra. This was a student orchestra put on by the Sewanee summer music festival. Top student musicians from all over the country. I was setup maybe 15' back from the orchestra. Very large ensemble with 70+musicians. Had alot of space to cover. I ran a center pair of akg 481's DIN with a flanking pair of Peluso subcards split 45' angled in 45* towards the orchestra. akg's ran into the ua-5 and the Peluso's into a v3. Mixed on the fly. Results were spectacular. Huge soundstage, stereo imaging is incredible. Very impressed. Probably one of my better if not best recording (to my ears) and my first attempt at 4 mics. Of course taping orchestra's are so much fun because of the wide dynamic range. This will have to be done again and will keep the flanking configs but may change up the center pair by using omnis baffled.
3. My sister's wedding reception, Labor Day weekend 2006 - We hired a bluegrass band to play all acoustic. It was outside on the front porch. I ran avenso sto-2's pointed at the outside of the group>ua-5 and AT 831's>bbox>line in (DIN). This turned out fantastic. It was a real quiet performanc since there was no amplification. I was set up 5' in front of them but still had my omnis much higher in the mix. It sounds wonderful. It will be a great gift to give my sister and new brother in law. Great stereo seperation even with the omnis.
4. NMAS a couple weeks back outdoors. I knew this would be thumping bass heavy situation and wanted to really capture the experience. I ran avenson audio sto-2's healy method>oade m-148 and Peluso cards DIN>ua-5. Very loud show and couldn't get the mix the way I wanted it. The 20db fixed gain was too much from the brick, I wanted the omnis lower in the mix but ended up with the omnis higher in the mix. The results are mixed. Great on home playback, waaaay to much bass for a car stereo. Not so much just boom as the highs and mids are very present, just that the omnis really picked up Chew's bass. Of course it was extremely bass heavy there so I account this to an accurate representation of the night. Next time I will keep omnis lower in the mix for a more pleasing playback.
5. WSP 2 nights ago. Split subcards (8' split)>ua-5 and mk4v's(ortf)>722>lineout>ua-5. I set the subcards just a tad lower in the mix. Results were fantastic. Torrent is up on etree if anyone wants to hear it. The mk4v's by itself will be posted tomorrow so to hear the differences between 2 and 4 mics.
Having to mix on the fly can be a bit difficult but so far most of my outings have yielded results surpassing my expectations. I like the idea of flanking mics. Omnis I will use more outdoors and the subcards more indoors (to block some of the rear bounce back) and hypers if I am far away from the source or cards if I am closer for the center pair.
Great topic, thanks for starting it Brian.