Sounds like you got a deal for the $500. I have 5 Airtronics Vanguard (not computer) radios. All are getting to be almost 10 years old. I have had nothing but great use from them. My only complaint is the trainer switch is a little weak and I have replaced 3 out of the 5 radios. In thousands of flights with these radios I have only lost one plane due to radio failure (that's pretty honest because lots of people crash and blame it on the radio). I was instructing when the trainer switch broke. I asked the student if he had control - he didn't. I didn't have control either and the Kadet MKII went in. It was only 3 hours of fixing and in the air again. That's a pretty good record for as many flights that I have had from the 5 radios. I would keep the Airtronics if I were you.