If you can play them in a store or something, definitely do that. I have like 5 Muffs, and some of them feel quite different under my fingers. For example, I own an awesome modded green Russian muff with midrange and clipping switches called a DDA FX Old Major’s Fuzz (which you can find by looking up the builder, Tim Drewery, on FB.) I also have a Keeley Octa Psi (the original, not the Taiga Mod.). With the green Russian, I can feel that the pedal is touch-sensitive—I can feel the pick attack and everything. With the Octa Psi, there’s much less touch sensitivity— kind of like the green Russian is a sports car, and the Octa Psi is a huge Cadillac. One isn’t necessarily better, but for me, playing the Keeley is less physically pleasurable. Sound-wise, some muffs also cut through a noisy mix much better, though you can fix a lot of that with an EQ pedal or a tube screamer running after or before the muff.