I have to say that it is a very well written and researched post. Kudos on a job well done.
Although I probably haven't had as much experience (have only played 4 or 5 toons with the DM Primary) as you, some weaknesses have become evident:
1) True...the attack chain is very fast, and Fury is ridiculously easy to build. However, how do you hold aggro? Although the design of the AT is not meant to be a Tank, that is in fact one of the roles we are forced to play. In practical game play we are needed to hold aggro. Plain and simple. How does your DM/INV deal with the difficult task of holding the aggro when his powerset limits him to being a single traget killer?
2) Soul Drain and Dark Consumption are powerful tools. However, the recharge times (post ED) can't be lowered enough to make them usefull to a Brute. While I admit that they are still quite powerful for a scrapper, they just don't come up fast enough to be usefull to an AT that needs to be in constant motion in order to maintain Fury.
3) Many of the attacks have 10% accuracy penalty (correct me if I am wrong). How do you deal with a primary where you have to automatically slot at least 2 accuracy SO's just so you don't miss all the time?
While I agree that the primary is decent (your numbers are 100% on) in practical play it just doesn't make the grade. I've herded level 42 mobs with my DM/INV at level 39...no problem. However, in reality he just can't compare to the type of aggro management that a SS/INV or Stone/Stone Brute can supply. They just don't have the dependable AOE attack that a toon needs for that type of play.
Case in point, in a mish with 2 SBr's and a Fire/Rad my lvl 50 SS/INV is doing 450-500 damage on every FS (up every 4 sec) and 1200 on every KB and this doesn't even include the rest of his attack chain (obviously this is at full Fury and Rage is up). Are you trying to tell me that your DM/INV is outputting that type of DPS?
Your math is excellent and your writing is compelling, but it just doesn't show the whole picture.
