The deflector def. does the job. However, it is already pitted up pretty good and I only have about 1500 rounds thru the gun so far. I'm sure I'll be replacing them a few times a year.
I hope you don't have to replace the deflector that often, they're $40 a piece! I have the same mount but I don't have the ports through the barrel, just a comp, and I have not been getting any residue on my lens.