Never tried it. Before it was banned in the UK there were some branded RC pills going around that contained MPA and MDAI. Apparently these produced a pretty good high, but there was speculation about it being neurotoxic. MDAI by itself I've heard is a bit underwhelming.
Yes it was nice and mildly euphoric. It required a stimulant mixed with it to enjoy properly. I used to mix it with mephedrone, which felt great, but for some reason it always made me sweat buckets!
When I bought it as a research chemical, I didn't realize how close it was going to be to MDMA. Nor did I realized that you can do it every day and you don't lose any of the effect.
Not to mention that the majority of MDAI is excreted from the body unchanged. That means your liver isn't getting pummeled.