I once had one of the little Mirage amps with a handheld. I don't recall it it was a 30 or 50 watter. Worked very well, I was pleased with it. Mirage is generally good gear. I have two Mirage amps. I don't use them and probably need to sell them. Just boxed up in the closet.
Sorry, I don't know anything abput the FT-90. Not much help, I'm afraid. There are some reviews on eHam.net, did you look at them ? Here's the link:
http://www.eham.net/reviews/detail/75
Jim