wlkjr, I LOVE Win231/HP38. The loads I worked up were great in the other guns, but a bit light for the Glock. I didn't own the Glock back then. W231 meters better/more consistently than Promo for me in my LNL. That said, the Promo variation is generally only .1 grain +/-, but I am at the Alliant listed max already. I haven't gone back to working up the W231 higher, but I may at some point.
Based on some excellent posts by BDS, I decided to pick up 16 pounds of Promo last year and work up various pistol loads, and I've been a miser with the remaining W231 until I can buy more of it. I'll tell you, yes W231 meters better, but I've been pretty happy with Promo in 9mm, 38spcl, 380, and I'm testing it in 32ACP as well. Another benefit of Promo -- if you run across it -- it only sells in 8# jugs and PV had them at $90 per jug. Other online retailers sell it for ~$100. Even then, it's a savings over W231/HP38 prices.
But, maybe I should tell you that it stinks and you shouldn't buy it -- leave it on the shelf for me... LOL
Those coated bullets should be just fine in your Glock. Others here have been running coated bullets with no leading issues.