I had a DSL100H and have a JCM 2000 DSL50. Tonally I think they're close enough for it not to matter - they all vary a bit anyway. I got rid of the 100 because it wasn't getting used and when I missed it I got the 50-watter because it seemed safer for my Greenbacks and I wasn't crazy about triode mode on the newer ones. Some observations: I like the digital reverb on the newer ones because Marshalls don't seem to need the springs for that surfy kind of sound and so the greater reliability of digital is worth the trade to me. The resonance control on the new ones is more useful than the deep switch on the older ones, but I rarely used either. External bias control on the older ones is nice. I prefer the tougher vinyl, rivets, and plywood on older ones to the softer vinyl, screws, and HDF on the newer ones. The older one seems to have the trannys placed in a way that balances better when you're carrying the head. The new ones are different. Maybe it's due to some difference in the amps wattages (different trannys?). Bias drift is a real issue, but you can avoid it or deal with it if you choose. The new ones do not have this problem and although I'd bet the older circuit boards are stronger, the newer ones are definitely smarter. All in all it's six in one hand and half a dozen on the other. If you find a good deal on one, don't overthink it.