I have snorted 2c-b and 2c-i as well as 5-meo-dipt. as well as my share of cocaine, mdma, ketamine, and on one occasion meth.
From my experience, the phenethylamines and tryptamines go in quite easy, but after about 5-10 minutes it feels like you get kicked in the face by a racehorse and then drug across the pavement for a mile a so, nose first. But the pain subsides shortly and the trip is kicked into full force very quickly. I would suggest a does for your nose should typically be about 1/3 to 1/2 of what you would eat orally.
Cocaine and meth, if crushed up nicley, go down fairly smooth, leaving a quick initial burn that subsides very fast. The residue (i guess, I havent really looked up how it works to be honest) resides in your throat for a good period afterwards, which is part of the pleasure of insuffalating it (IMHO)
MDMA leaves a harsh burn for the first 10 or so minutes, but after that the burn goes away and you are left with a very chemical taste in your throat, which then leads to a very nice ride.
Ketamine hurts horridly, like little razors, but not for long, and not if powdered VERY fine. The onset of effects from this (my meory is a bit shaky on it, it has been a long long time) is very quick, and the k-hole is much more intense.
I have seen people insuffilate phenethylamines with very adverse effects, including foaming at the mouth, vomiting, nausea and reportedley, very intense headaches. However, I did not suffer any of these effects from the same batch, but I did see others in that state. So I am just giving a heads up. It may have been that the chemicals were not too clean, but like I said, I did not have these bad effects, just a strong burn at first.
Thats my 2 cent