Black-T scratches fairly easily, I think. No experience, just from reading.
Personally, I'm sending one of my 2.5" Model 19s to that vendor you mentioned earlier in the thread for a matte DLC. It's been a fantastic finish for me on my G19M. I've seen a G19M go skidding across concrete and it didn't even show a mark. That shit is tough.
I've got two other retired matte Model 19s from my job, figured I should make a beater facsimile (but with a tougher finish) that I'm not afraid to shoot a lot.....the 4th 2.5" Model 19 being in NP3 inside and out. Might be worth noting, but the trigger job on the NP3'd Model 19 is noticeably better than the trigger job (from the same 'smith, Sandy Garrett at NoVA Gun Works) on the carbon steel/blued Model 19.