I don't have much experience with marathons, let alone trail marathons. I'm a collegiate middle-distance runner, doing summer marathons in the off-season. This was my first trail marathon, and all I can really say is it was a great experience. I have no complaints. For a small, low key, environmentally friendly race, I thought it all went very smoothly. The course was beautiful, and Mackinaw City is a fun place to be for a couple days. There are lots of little, fun activities to do the night before and after the race.
As for spectators, there are only six or so points along the course that can be conveniently accessed leading up to the final mile. Not a huge deal, but viewing the race is significantly restricted.
Overall, I definitely recommend this event.

This race was run point to point on the North Country Trail through Wilderness State Park at the top of Michigan's lower peninsula. Just about every type of terrain was encountered from very serious hills, technical root filled sections, swampy mud, old two track, and some beautiful sections of single track. There were some simply beautiful views of lakes and forest when you could take your eyes off the trail. The course was very well marked with mile markers included. The support was adequate with stations at about every five miles (you were required to carry a fluid container) and the only spectators were at the aid stations except for a couple of stray park rangers along the way. Prerace organization was fine and packet pickup was simple. Mackinaw City offered plenty of things to do before and after the race. My only complaint was the poor post race refreshments... Some dry, stale muffins and scones, watered down cherry juice and water, no fruit and no beer (I'll bring my own next time). Still this one was a lot of fun and a race for those who like beautiful scenery and a challenging trip.