Never sat in a blind for Idaho Pronghorn... the 21-A hunt may have some locations that lend itself to waiting in a blind in 100+ degree temps, but I haven't found one nor would I want to. When you hunt Spot and Stalk, you have the opportunity to make things happen, pick out the buck you want and dictate the rest. While I won't give out specific areas to hunt, I will say there are a pile of great locations to hunt with the 21-A tag.
The first year I did the 21-A hunt, I went and hunted 19 times. I had 31 stalks. I am embarrased to say how many resulted in a shot, so I won't. No animals were wounded and I missed a great buck on the last day at 12 yards because I was too darn excited.
This past year, I hunted 3 days, did nine stalks and took a great buck. I had shots each day and either passed them or missed.
What I learned after the first year is that you need to wait out a buck for the best opportunity to get close. If you are stalking a group of Pronghorn to get to a particular buck (common to see herds of 10-15 doe's with one buck), focus on the lead group of doe's and stalk her (them)... He will bring up the rear usually and come right by you. Once I learned that, it got easier. Still, not simple by any means, but it made the hunt a bit more enjoyable.
There are a few unlimited hunts that only encompass one unit, but you can't beat the 21-A tag for the amount of land you can hunt... I think it's 17 units or something, archery only, before the rifle hunts (all draws).
Spot and Stalk Pronghorn hunting is fun, in fact I think I enjoy it as much as anything else and they have easily frustrated me more than anything I have ever done with a bow in my hands.