This is my experience, I have months of steady cocaine use, years of (meth)amphetamine use. At my worst, I was basically consuming whatever I could, however I could.
Cocaine as a drug? I find basically zero use for. Sometimes I feel good, sometimes I dont. Most often I am just anxious and want to take more. I don't really find cocaine to be euphoric unless I take a big line right after waking up, or unless taken IV. I have never smoked crack. Mainly because I am certain that I would love it. The IV cocaine rush is very hard to describe. It's very fleeting but insanely euphoric, both cognitively and physically. IV so far is the RoA that I find to be worthwhile wish cocaine. I witnessed one friend acting almost dunk after shooting an un measured amount of cocaine. For at least 30 minutes he could hardly walk and was very dis inhibited.
Math, I actually personally think that the best rush comes from hot rails, followed by smoked. Oral also can provide a pretty good eush. Both IV and Rectal dont provide a super euphoric rush ime. Don't get me wrong, either route feels fantastic; but as others have mentioned, it feels more like an instant plateau followed by a slow comedown. IV meth is great when consuming a large amount almost instantly, but hot rails feel the best imo. Yes, some people cough after a big IV shot of meth. I'd get the cough when shooting 100mg +. It seems more common in people born female, but some people will actually orgasm after taking a big shot of meth. I have come very close myself, but never a full orgasm