Not bad, now let me do it. I have been reading and writing chinese since I was 5. Please don't let the fact that I am still 5 mentally put you off..
A more accurate translation:
"(No problem, just to tell you) I have been comparing the actual product (A3120 diver I presume) against the genuine article the entire week, and am surprised at how close the A3120 decoration is, virtually indistinguishable from the genuine movement upon casual inspection. Given the fact that only 400 genuine watches are produced (for the ceramic I assume), there wouldn't be many in circulation and not many guys would have seen the genuine article. Please share this."