I haven't had the chance to setup a proper way to record the cabinets, I didnt some more side by side testing as well as both combined. I am sure that when mic'ing the speakers the results will be different but while just cranking them and hearing them in a room this is what I have noticed......
When cranking up the bass to around 2-3 o'clock and playing some tight riffs (think heavily muted megadeth, metallica riffs) the peavey with the sheffields move some air and rattle your balls while staying tight and punchy. They sounded great. The rec cab with the v30's flubbed out and got harsh.
When I backed the bass to 11-12 the v30's cleaned up quite a bit they also have a mid range "bark" that I think would cut through with a band really well.
Combined they sounded amazing!!!!!!!
I am thinking of experimenting with an x pattern with the v30's and either sheffields or 12t-75's, my only problem is that the v30's are 8 ohm and the sheffields are 16. I wonder if I could rewire the cab so it'll run in stereo with 16 ohm on one side and 8 on the other? Anyone have any suggestions?
Another option which I think would be great is running the peavey 4x12 with a mesa 2x12 on top of it. Then if I start gigging again I could bring just the 2x12 on some gigs.