Well someone correct me if I'm wrong but the commonly used cut msm gives you a warm flush which lasts 5 sec or so, I guess I'd say the msm rush feels more like your skins gone red and warm and your overheating a bit but clean stuff is more like a pleasant vibrating/glowing euphoric feeling that creeps gradually for longer like 15-30 Min depending on tolerance n size or thickness of the shot. Also a decent one will take your breathe away, not so much a taste but almost like Halfway between the numb feeling from coke and a fisherman's friend haha
Both will increase body temperature due to heart rate and pulse increasing though the msm ones dirty/unpleasant feeling compared.
Also depends on your gear, older red phos psuedo based gear had more of a rush and quite often back in the day hadn't been cleaned fully and would have a stronger taste but the ice these days is a more focused high with less euphoric rush. When I've been hitting it to hard n dopamines depleted I will barely get a rush too just back to awake/alert
Msm leaves you abit jittery or scattered aswell, some people get headaches and it seems to shorten the duration of the high from the actual gear that was in the shot
I've only been mostly shooting it for a few years and for the decade or more before that mostly smoked so I'm sure there's others here with more of an idea.
I find some really cut stuff will have abit of a chemical taste too but it's more of an actual taste instead of the breathe taken away feeling.