all in all pinckney isn't that bad of a place to go. the hike in was pretty easy, took about 3 hrs on the way in not to break a sweat but i did it 1.5hrs on the way out with a good sweat. you can easily drop off at any of road crossing if you're looking to shorten the hike and then have one person do the complete walk in.
we did all get tickets for not having the back country permitt but there wasn't any forms to fill out so we assumed they would have a post at the campsite to self registar. the park only had vehicle registration at the main entrance. got a phone call from the ranger station late last night, chatted for a while, explained the group and all issues are closed.
if you're looking for a relatively close over night trip i'd recommend going. they have a nice out house with trash bin and TP, little cold on the bum, no smells, plenty of down wood but after chatting with the ranger i guess they passed a law saying you were not allow to remove down wood now - implemented 3 yrs ago but most places are not enforcing it.
the rangers all seem pretty cool, i bike out there a lot in the summer so i know the trail pretty well, some may find it hilly for Mi, but from what i gathered as long as you give an enter/exit time, party count and stay at the campsite they really don't care when you coming in, leave or how you choose to walk in. oh, and i gave a trip report on down trees, trail condition which saved them a trip out there for looking.