Every rig sounds different, and the tonal goals of players vary, but to say a light rig can't compete with a heavy one is overgeneralizing, and also not true. I use mostly lightweight class D amps but also have a class A/B and a full-on tube head (65 lb Super Bassman). For some gigs/situations I like the SB more, but others the SB doesn't really work. To those who say they'll sacrifice a little tone and volume to lose the extra carry weight, I say, you don't have to. One might , say, prefer an SVT 4CL to a Quilter BB800, but it really has nothing to do with weight. A heavy amp, on average, is NOT better than a light amp.