I own two Ameritron amplifiers and I haven't really had any trouble with them. Well, I did have to send my AL-800H in because I melted the LF Coil, but I'm not all that sure that was the amplifier's fault (I suspect some abuse from a previous owner after I got the diagnosis back from Ameritron). I've been using an Ameritron ALS-500 mobile and have not had one single problem with it.
There are certainly nicer amplifiers made, but for the price and function, Ameritrons fit the bill for me. Now they have that ALS-1300 solid state amp, which is nice becuase you don't have any warm up time. One other good thing is that Ameritrons are made in the U.S., so you can get them serviced here if you have a problem.