I only know of two possible problems with Blackhawks. With the New Model guns (where just opening the loading gate allows the cylinder to spin for loading) the chamber holes do not line up with the loading gate when they click into place. You need to look at them as you load, to finesse them into the right position. Old Model Blackhawks and Colts and their copies line up perfectly, and you can load and unload by feel, without looking. This may or may not be an annoyance to you.
I have heard of Blackhawk cylinder pins launching downrange, under recoil. I have never, personally, seen this happen. I have two 357s, a 41, 2 45s, a 44 and a 30 carbine blackhawk, and have never had a problem with this, but the reputation for it happening is out there. Belt Mountain base pins were invented to solve this problem. So, if you have it happen to you, you can get one of theirs. http://www.beltmountain.com/