I actually come out of months long lurking after reading all the bad things about 4-MEC..
I gotta share my story with this one. I am familiar with both Mephedrone and Methylone from when they were easily attainable on-line in the US. I didn't touch any of the stuff (uppers) for almost a year after a bad experience with a dodgy "6-APB." I decided to have some hedonistic time at the end of the work-filled and boring summer and tried to seek out Mephedrone or Methylone (preferred by me, less went a longer way and didn't make me feel as bad next day as during the coming down from Mephedrone).
What I've got in the mail turned out to be 4-MEC. After talking to the vendor I found out that almost no one makes good Mephedrone anymore, bulk suppliers are really scarce and hard to trust, so everyone is going for the "next big thing" - 4-MEC. Anyone who wants to find legit meph online these days - good luck, as you probably are out of it. Or you can expect getting some "gods know what" instead.
In my case I am glad that I crossed the path of 4-MEC.
My observations (using an almost pure white, no odor crystalline version):
For me it takes more orally to achieve the same effects (intensity of feeling) as with MCAT and M1. I found two plateaus with this one. 150-200 mg will give me a nice relaxing high that lasts about an hour or two the most.
Risking taking 300 mg was worth it.. It brought the experience to a truly new level: I felt relaxed, very euphoric, empathetic but a little withdrawn. It was a very blissful feeling, like electric current was sending waves of pleasure down every single part of my body, my heart beat rate wasn't much higher than the baseline. Anyways, it felt very awesome. The only downside the bliss was almost gone in 1.5 - 2 hours and that's when the side effects kicked in all of a sudden. High heart beat rate - up to 140 beats a minute, unwanted stimulation, restlessness.. However, I had no problems falling asleep after two shots of whiskey with apple slices. . I have a pretty active lifestyle due to the nature of my work and I've been in a decent health, that probably helped a lot.. Even after a 1 gram binge of 4-MEC (every single re-dose brought me back into the bliss-land) I could fall asleep the same night. And in the morning after about 6 hours of sleeping I felt a little tired, a little wired but managed to go through 8 hours of physical work no problem. Nothing like feeling of the whole world crushing down on me for almost two days after binging on MCAT and M1 from the past. A great plus.
Maybe the high is shorter and it's not the same as from Mephedrone but it doesn't mean that it's worse. When I look back at my experience with meph and M1 I remember mostly a bad hangover, while when I look back at my recent experiments with 4-MEC I remember how great I felt and how my body didn't hate me for it (as much).
On the second occasion I had 4-MEC I had about 250 mg, went swimming on it and it felt great, my heart didn't bother me at all. On the come down (about an hour later plus maybe 15-20 minutes) when it started beating fast I had three quick beers (I can drink a 6-pack no problem and feel only mildly intoxicated afterward) and in 15 minutes I was napping in a car (in the back seat I must mention)!!
In 30 minutes when I got home I almost felt fine again, like I wasn't taking anything 3 hours ago!
The music appreciation is there.. Singing and playing guitar felt awesome, too. I felt like I was in full control over my voice and emotions in the lyrics. However, all the good stuff goes away during the comedown and turns against you - music irritates and it's hard to find some sort of a task to pursue and keep the mind on.. Damn comedowns. .
4-MEC is better than Mephedrone for me, however, stuffing the stuff up my nose was a bad experience. I think it should be better taken orally in high(er) doses and to be avoided inter-nasally completey. Effects this way are even shorter, more pressure on heart and body, plus even after washing my nostrils after each line and chopping the crystals into a fine powder I had nosebleeds for two days ahead. And I didn't snort more than 300 mg that evening...
I didn't crave it too much and could stop when I wanted to stop (I split 2 g between two sessions), even though it took self-control and knowledge from the past experience
And if anyone is curious: I am 6'3", 210 lbs.