I could honestly go gloss or matte. Gloss looks great on any gun, but Ive seen some matte Traumas that look amazing. I would say go with gloss unless its got some crazy milling. Gloss tends to make milling lines fade imo. Matt seems to make them pop a bit more (hence the Traumas)
I feel the exact opposite, I feel gloss catches the light and makes the grooves and cuts sparkle........lol. I prefer gloss all the way, Im actually moving my DM7 up to the next gun I do. Its matte, I might or might not keep it that way.......havent decided.