Not too well, since I usually try to avoid this class of substances. I've tried 4-MEC which was OK, imho the best "substitute" before there was 3-MMC. I think 3-MMC is even better, though maybe it's just my personal thing (set, setting etc.). 4-FMC was definitely the worst substitute, found it only enjoyable if mixed with alcohol. 3,4-DMMC was very pushy, gave me quite some rush, but it didn't feel serotonergic at all. Also, the needed dose was terribly high (300 mg oraly and 50 mg snorted) and felt like there's still some room left to go higher). 4-MeMABP was plain junk, giving a rush (250 mg oral) that was not too enjoyable and very short lasting. I have not tried 4-Ethylmethcathinon and usual MCat yet.
I'm not saying it's superawesome but if someone is looking for a good 4-MMC substitute it's definitely worth a try.