The slide stop mod is very subtle.
I had Rick do it as my last carry guns were USP/USPC models and I was used to that wide slide stop they have.
Rick adds some material to the surface to make it just a bit more substantial and refinished the part. It does make a difference for me, but YMMV.
The change is subtle enough that it did not impact the gun's fit in the fitted Ritchie and Kramer leather holsters I use. It is almost invisible to the eye, but you definitely notice it when you run your thumb over it.