I've watched iM@S Xenoglossia before, but it's been so long that I've forgotten most of it. I remember it being pretty standard but liking it well enough though. The OP and ED themes were pretty good too, I guess.
It was out like 4 years before the normal iM@S anime adaptation, and used different voice actors for all the characters. I'd guess those were why it wasn't quite well-received by pre-existing iM@S fans at first.
On a side note, the series also released albums with the voice actors covering old mecha series' songs. I especially like Makoto/Kitamura Eri's cover of Honoo no Sadame.
https://www.youtube.com/watch?v=QiDM4FJxU1I