I used the 50/50 stuff once when finishing up on a '50 Mercedes where I didn't have easy access to water. Easier than carying 2 jugs. As far as I could tell, it worked the same as mixing it myself although maybe a bit more expensive. It was convenient though.
Zach, the Oklahoma heat can get to you a little but not a s hot as south Texas though. Like davey said, a little more water in the summer and you might try some of that water wetter stuff. I can't remember the name right now but it does seem to work.
Bayless
Never express yourself more clearly than you can think
'48 Prefect
'67 Sprite (project)