A Druid friend of mine tested it in cat form and he told me he got a VERY small amount of procs. He didn't record anything, he just told it was a "feeling", but this makes me believe the PPM proc chance isn't calculated from the Druid 2H weapon.
That would have been insane, having a slow 2hander being used to calculate the PPM proc chance, and then being able to proc it every second in caform. So it need to be confirmed, but it seems the 1.00 caform attack speed is used for PPM-based procs, makin this trinket not better / overpowered for a Druid as it would have been if the weapon speed had been used.
Regarding the procrate, nbody can say for sure how it was during retail, but actually 1 PPM makes it a decent trinket pre-BiS or for PvP (especially has a Hemo Rogue with a slow MH, due to the proc chance being a PPM).
The sources regarding this trinket proc-rate on retail are actually quite different from each other, some of them suggest a PPM-based thing, some other just state a flat proc rate without any information about the way it was calculated or the weapon speed used etc., it's actually not that simple to know how it worked exactly.
In my opinion 1 PPM seems to be something close to what it was on retail: a nice trinket, in PvP or low-tier PvE, especially when Dual Wielding, but with better alternatives.
For a Rogue, having the DMC:M will yield just as much procs as Crusader prods if they had 1x Cruader enchant on each hand for instance (since Crusader is 1 PPM too).
Undertanker wrote:PPM was not a thing in Vanilla. Procs could proc off themselves, these were all static based %, so the more special abilities you did gave you more procs.
You are spreading false information :'(.
PPM was a thing in Vanilla. Just not the way you might be thinking of it. You are right, the actual 'Proc Per Minute' mechanic that meant "this proc has an internal cool down" was added later, but in Vanilla, many enchants and procs (possibly the DMC:M too, if you read above), used a 'Vanilla-PPM' mechanic, if I may say.
A proc having 1 PPM in Vanilla just means that if all your swings hit the target and you only auto-attack, you'd have 1 proc per 60 second of fight, in average. Thus, special abilities being instant and the same proc chance being used for them, a slow MH weapon gives a lot more procs than a fast one for 'Vanilla-PPM' procs.
Undertanker wrote:The only limited proc item in Vanilla days was crusader enchant, and it wasn't long. It was implemented to help avoid stacking of crusader..
Crusader was indeed using a PPM mechanic. But the 'Vanilla PPM' one described above. There was absolutely no internal cool down on Crusader, you could proc it twice, whether from the same weapon or not. And this is the same for most enchantments in Vanilla (Fiery, Lifestealing).
Just see http://rogerkarlsson.com/blogs/wow/crusader/ or watch any video and you'll see it was possible to get two crusader prods in a row, even from the same weapon.