It can be as simple as a few dot points about what you do and don't like about the POM. The link to the NPWS has a form where you can put your info to submit to them.
If your into DH, I would suggest you won't like the loss of the DH trails.
If your into XC, you'll be pretty happy with the formalisation and recognition of the northern trails, but maybe a bit unhappy about the loss of the south.
The earlier posts in this thread go through the specifics of the POM a bit more. There is also a lot more info on the Glenrock Trail Alliance Forum. there is a link in my signature to that one.