I love Marshall especially for lead, the rhythm crunch to my ear is tighter than on Mesa which has a lot of sag but does sound heavier. I get the best result from Marshall gear with the distortion/gain at between 1 and 2 o'clock. It is extremely tight and heavier in my opinion that going all the way to 10, which gets noisy and dirty in a hurry. The amp is only one part of a guitar sound, it starts with the pickups but gets is character from the hands. I have both Mesa and Marshall gear, I like them both equally. ONe thing about Marshall is the tightness and creamy distortion, you can push some serious air going through a good combo too (check out the TSL series). All about preference at the end of the day, I would certainly rate Marshall gear very highly though.