I have the Int-250 which I use to power Wilson Sasha 2's and before them Maggie 3.7's...I am quite happy with my sound now and what they did for the Mag. I have had them about 9 years without a problem. They can go quite loud if you need them to but clean and the sound never sounds stressed.
Can't say that I have been able to compare them in my system with others but I am not looking to change them. So I can't tell you how they sound compared to others but I am a happy camper (owner...)