I had been using the UT-72g for a little while, and I had no problems with it at all. I am very new to GMRS, but it seemed to perform very well for me.
I just recently got a MXT-A26. I have only had it on for about 2 days now, and the weather has been really bad, so I haven't been able to use it much. We also don't get a hell of a lot of GMRS traffic in our area. So I really haven't been able to compare them much yet.
But the UT-72G seemed great for me. I also live in Southern Colorado, by a lake, so we have some plains and mountains.
