I just got Mesa back 4x12 cab to go with ED and it's quite interesting.. It's loaded with C90. I also got Mesa 2x12 recto cab with V30 which I really like. The sound is very different with these two cabs. Allthough I like both cabs I like the intensity of recto cab. Have any of you got experience with open back cabs and ED? Any hints settingswise? And is there big difference if I substitute C90 with v30 in 3/4 cab?