without a doubt, my money would be on the diezel front load - build quality and sound quality to me are awesome. when you have a peek inside, there are 3 solid baffles and the cab is deep which i am sure makes much of the difference, other than the speakers projecting more front loaded. the cabs response to speaker changes is very dramatic, where i would find with any rear load. as a matter of fact, i am contemplating maybe a 2x12 front load cab and slap some celestion g12-k100's in it to compliment the other with the vh4. the uberschall will stay with its ubercab, which is also a great cab. i wouldn't pay the money for the mills as there is nothing special about it.
steve