Shot in the dark, but I've had an old brake hose give the impression the caliper was bad. Sometimes the inside of the hose deteriorates and as it does it can act as a check valve trapping pressure in the caliper.
Replacing the brake hose is relatively easy and inexpensive thing to try.
-Dan
12-25", or 13.5-27" should be a good height. If you are tall the extra 2" might make the difference. Just make sure you can comfortably shoot from a sitting position with that height to allow you to get over the sage that is present in antelope country. The swivel is a nice feature as well and...
I've found with a traditional style stand I move more because I'm uncomfortable. My back resting against a trunk just doesn't work out well for longer periods of time. With a saddle my movements are to keep the trunk between me and deer, or to alternate, slowly, between sitting or leaning...
When I can rifle hunt.270 Winchester. For factory loads I favor Hornady American Whitetail, 130 grain.
Here in southern Michigan we are limited in firearm selection to muzzleloader, shotgun or straight walled cartridges. I've been having good luck with a .450 bushmaster. Probably over gunned...