It's lousy. Some people have managed to get not-very-good empathogen effects by escalating the dose unreasonably, most are unimpressed by it. I found that at s tiny tiny dose (10mg or so?) it produced a feeling of sadness and emptiness lasting several hours, with no recreational effects to speak of - sure glad I didn't take more.
There's a reason everyone lost interest in this stuff (mostly, the vendors got their sample batch in, tasted it, and realized they'd just wasted a few grand on a custom synth of garbage and canceled the bulk synth). Many of the positive reports of 5-IAI are actually from other compounds sold as 5-IAI (I got a batch that was a nice stimulant - testing revealed that it was in fact cathinones + god-knows-what. Another vendor sold me mephedrone as 5-IAI); a lot of vendors were doing crap like that last year to make a quick buck after it became clear that 5-IAI wasn't the next meph.
! It's a shame that all the good products (methylone, mephedrone) are so difficult to find now...