They are really different. I like the VHT for a great live power amp if I'm doing a rack thing, but I think there is actually too much headroom. It just has to be stupidly loud before the tubes get that throatiness and mild compression that I like for live or recording. The MOD 50 gets there in low power mode much easier and with a range of tubes. Although you can use 6l6s in some 2-50-2 models that have a switch in them for this, the VHT still doesn't feel like it was really designed for this in mind at the git go. In the MOD 50 by comparison, the 6L6s sound huge . I won't get rid of the VHT because it is the best stereo power amp I have heard though. Also, the VHT presence controls behave more like a tone control, whereas the MOD 50 presence behaves like a tone with gain effects in the upper freqs (which I prefer). The VHT depth and presence have more of a usable range than the MOD 50, but the MOD 50 density and presence dial right to one place where it sounds super musical to me and I just don't want to budge it it sounds so good.