Hey, I'm from Ask Mr. Robot. We are up-to-date on the new real PPM system and all of the trinket proc info - in fact, we had it updated within 24 hours of the information being posted
We do extensive tests and track down as much information as we can to double-check our results. I'm still stalking the forums to gather as much info as possible.
Our ranking system is
described here. It's very, very thorough and we
publish the results of the trinket procs here for each class and spec.
Note that our process simulates the trinkets to get the average amount of the proc stat you'll get over time. While this is really good most of the time, it does not take into account lining up procs with specific ability cooldowns, etc. For example, there is one trinket in particular that only lines up once or twice in a fight with the Ret Paladin's major cooldowns. So we are working on a way to account for those types of cases.
My recommendation is to use Mr. Robot's ranked trinket lists in conjunction with our trinket pages. Then Sim your character in SimC (we have an export option), and analyze the results. Trinkets tend to be a personal preference as well, so once you pick the trinkets you like, lock them in. Mr. Robot will select gear around those then