Wear, minor flaws....
When I purchased a NIB surplus 96D .40S&W pistol in 1997, I used a Aker black leather shoulder rig & wore it concealed often.
Over time, I never had any wear marks or spots/scuffs on the firearm.
The Beretta 96D .40S&W was treated with Robar's NP3 & was intended for a Fish & Game law enforcement agency.
The 96D did have a few small streaks where the slide & barrel made contact.
This is common with nearly any semi-auto pistol.
As posted, the Metalife SS C(a treatment suggested by "Chuck Taylor", a well known gun writer & instructor) & Robar NP3+(the new format of NP3) can hold up to EDC(regular carry).
I use a Blackhawk SERPA holster with my new S&W MP45 Compact .45acp.
If the Melonite starts to wear off or streak a lot, I may get Metalife SS C.
The process is only $78.00 with $10.00ea for extra magazines.
Clyde