Consistently slow domain logins / folder redirection

I've been trying to diagnose slow logins to my domain. One of my first stops was Domain login very slow 10+ minutes.

So far I've been able to tell it has to do with my policy that applies folder redirection and administratively assigns offline files. Enabling this policy reliably adds from 30 - 90 seconds to the login.

This happens even on profiles that only have 20 megabytes in the redirected folders.

I went through a number of articles including suggestions of using procmon to see if a hangup is occurring. I did find and fix a few second hangup on an old scheduled task, but nothing near explaining this long of a lag.

I also looked at a couple of the active installer suggestions - such as the mail app.

What else can / should I check out before I break out Wireshark?

Edit for the questions:

1. This is occurring every log on. Software settings / etc persist as they should. There are no temporary, mandatory, etc profiles in the mix.
2. I see activity via procmon, but nothing that indicates a gap. No gaps event times, no processes with extended duration.
3. I previously turned up the verbosity on the file redirection logs. Based on the folder redirection operational logs it takes under 1 second for the policy to process (event 1000 to event 1001)
4. The group policy operational log shows a couple of my more complex policies clocking in at about 1 second each.