So is this one you like and had good luck with or one to avoid. I'm trying to get you to be specific. You say you have seen 3 unique designs, I have no idea what/ where those were/ are.
I did all that several years ago so it is a bit foggy what the brands and designs were. That Murray one I just bought lasted all but a couple days before it would not work..... I had ordered one from Classic Auto Air but they take a few weeks to get it out so it was on order when I bought the Murray locally. I have been crazy busy the last few weeks dealing with some family things but did put the Classic Auto Air TXV on and we took it on a 500 mile trip to a show last weekend through 75F to 100F temps. First thing is Classic get $70 for their valve vs half that for anywhere else. The valve I received was different. I was expecting just the same old Murray, Four Seasons, or other common aftermarket low quality design but it was different so maybe they have put some thought and engineering money into their own valve. All I can say is with the Classic Auto Air and charging it with the correct amount of freon buy measuring the subcooling it worked not as great as the Coronet but we did not sweat the entire trip. if the temps were below 90 it worked great and it felt cool. Above 90 it was not uncomfortable but it left you wishing it was about 5 degrees colder. Before above 90 it did so little that it was uncomfortable enough you would rather have the windows open. This weekend it is supposed to be 110F in Tucson so I am going to spend some time looking at a few optimizations in the heat... you really need to do your testing in the heat to know if it is working. I will make a video of that work this weekend.
