I haven't said anything in the DM threads yet because I still don't know which actual problem the introduction of DMs is trying to solve.
IMHO the current process with sponsors reviewing and uploading packages has proven to work nicely, i.e. the amount of broken packages uploaded is not too high. Most of the perceived problems with this process stem from the fact that most of the packages offered on debian-mentors or #debian-mentors are initially crap and need lots of review cycles. Once people produce good packages asking the last sponsor for another upload should work. (And at that point NM will be a breeze.)
Particularly I don't like the fact that the "initial policy for an individual to be included in the keyring" does not include any check of any technical or non-technical skills besides having a gpg key and be able to tick 3 checkboxes. I fear this will lead to people blacklisting "DM" packages because they don't want low-quality packages on their machines.
At the same time, the rest of the GR text is micro-managing every other detail of the process in a way that doesn't leave much room for practical implementation decisions.
It appears to me that the DM concept as sketched in the GR is mainly meant to let NMs upload earlier, i.e. it tries to fix the fact that front-desk or DAM approval take too long. I think the fix for that is just to find someone besides Joerg to also read the AM reports. DMs as in the GR are a workaround, not a solution.
On a sidenote, I'm still wondering why front-desk (and afaict the DAMs) were never asked about their opinion while/after the GR was drafted. I had some chats with Anthony on IRC on the topic, but that was shortly after Debconf 6 (there was a related BoF), nothing in the past months.
(not with the front-desk hat on, but having it within reach)
PS: I voted "-1".