I took my new GP100 to the range tonight to shoot 50 rounds of American Eagle .327 100 grain JSP and 50 rounds of handloaded .327 (100 grain Hornday XTP over 5.5 grains AA#5, CCI primers, Federal brass).
This is an excellent handgun in .327 Fed Mag! The fairly hot American Eagle factory rounds had a lot of blast and noise but the 40 oz. GP100 made the recoil reasonable. My handloads, designed to be mild, were like shooting .22's.
I recently added the HiViz front sight, which was easy to see in the indoor range.
As a final bonus, the revolver is pretty clean after 100 rounds. All charge holes are clear and fully useable after 100 rounds of ammo (I think the .327 Fed Mag is a little prone to having problems with build up inside charge holes, making it hard to insert rounds or extract brass, based on its narrow/long dimensions).
Bottom line = great experience. In response to the OP, I don't know of any problems with them and hope you can find one soon.