Inactive AMs
The most common (and, in fact, visible) complaint concerning the New Maintainer process is the time it takes for the DAM to approve the applicant and, after that, create her account. No need to rehash over that.
Another very common problem seems to lie at the AM level, with a number of AMs being mostly inactive, as far as the NM process is concerned, for long periods of time. I know a number of NMs who are waiting for their AM to, basically, come back to life.
It’s not OK for an NM to have to wait for months for her AM at whatever step of the procedure without any reply whatsoever to her mails/IRC pings. It’s even less OK to have NMs wait for months for their final AM report to be posted on -newmaint.
The problem is not with the time taken by the whole procedure (though that can be improved too), the problem is with unresponsive AMs. If you can’t keep up, give up. Don’t let your NMs wait for you indefinitely.
It’s even worse when the AM wants to be the exclusive sponsor for her NM. That means the NM cannot properly take care of her packages in Debian. That’s not acceptable. That practice should be discouraged.
And, oh, this works both ways: if you’re in the NM queue and have time constraints impacting your application, please tell so to your AM and ask to be put on hold until you can find enough time to resume your application. You’ll help everybody by doing so.