I have several Burris Fastfire 3 units on a few different guns. None have ever given me a bit of trouble. The one on my SBHH 44 was dropped (with the gun) and never lost zero, despite bending the aluminum frame of the sight a bit. I am quite pleased with the Fastfire 3.
As a side note, the Weigand mini mount you mentioned just arrived at my house to go on a Blackhawk 357. I haven't installed the mount yet, but it will wear a FF3 when I get time to put it all together.