If you have watched YouTube videos on removing the stock rail, it requires nothing less than brute force which aesthetically destroys the stock rail. This Troy rail fixes all of that with three easy screws.
Pros: Easy to install! The rail Sig provides is proprietary from the bottom rail being blocked for accessories/rail-covers to the dove tail gap left after removing the front sight. A+++
Cons: The portion that covers the upper receiver is slightly larger and covers half of the punch dots...BFD!:-)
This review was written in the old system and had content requirements that are different than reviews written today.