As per my knowledge the default positions of all the amps and fx really seem to capture the "essence" of that thing, whatever it may be. In other words, if you want that classic AC 30 sound from your amp, drop in the AC30 model and it's pretty much spot on with minimal tweaking. I find that to be insanely useful. For almost any OD, or amp model.
When it comes to the comparison you should consider the PCB and its design for the AMPs as well. Different manufacturers have different strategies for the PCB Turnkey Assembly and when we switch the wattage of Amps then it has huge impact on the PCBs.
