*This got REALLY long.....skip to the bottom if you're in a hurry.*
I just did parts of the Northern Tier and Northern Lakes route and finished a few weeks ago. Maybe being from the Pacific Northwest, I'm spoiled, but there was about 200 miles of the UP that I could have done without. It was worth every minute of it, don't get me wrong, but there was about 2-3 days of "road with trees on both sides". I had a long talk with a friend of mine to describe it and I read her my journal entry:
"It's all forground. There is no background. What you see directly in front of you and to the sides of you doesn't really change much. I'm used to the NW and there's a mountain in the background pretty much everywhere and it seems to move around in the background and you get closer to it, or you veer in another direction and see a different one. Not so much here. It's much hillier than the maps topo shows. The rise and fall isn't enough to show on the map but there are hills here...one after the other, after the other."
I met a couple other cyclists going the other way around and they pretty much said the same thing. Kind of monotonous and much more elevation changes than they were expecting.
I started/ended in Platteville Wisconsin and started the ACA route starting in Marquette, IA. The Mississippi River was fantastic. You'll really only see it for a day starting in Minneapolis following the North Lakes route, which is too bad. I really enjoyed that portion even though Iowa was brutally hot and had more changes in elevation than I had ever thought possible. The Minnisota portion was awesome.
I veered off route at Clam Lake Wisconsin and made my way north to Ashland because I'd never seen Lake Superior and it was only 50 miles or so. Nice town (Karl at Bay City Bikes was a godsend) and a very nice ride. I took Hwy 2 and 51 south to pick up the route again near Mercer. From there to Escanaba was tough for me. It was unusually hot and the scenery is noted above. Services were ok, but mainly gas station/mini marts. Fruits and vegitables were rare for a couple of days. I found 2 bananas in 3 days and they were nearly black. After Escanaba services were more plentiful and the scenery was fantastic all the way to St. Ignes. You're also on Hwy 2 for a good part of it, if not all of it. Lots of traffic as it's about the only road.
Basically the route from Escanaba to where I beelined to Muskegen, where I took the ferry to Milwaukee and back home, was a fantastic ride. I did ride the 20 miles or so "Tunnel of Trees" where the maps say not to because of traffic. Personally, I'd ride it again in a heartbeat. It was one of the most memorable parts of my trip and the shade was a real treat.
I beelined from Milwaukee to Platteville, through Madison in two days, mostly on the Hank Aaron, Glacier Drumlin and Military Ridge trails. Personally, I didn't like much of it. But, I've also been through that stretch a zillion times so it wasn't new to me and I put the hammer down.
A week after I finished my tour, I headed back up to the UP and into the Keweenaw Peninsula for the first time and car camped with a girlfriend who went to school in Houghton some years ago and wanted to go back and see it again. Wow. I can't believe I pedaled so close to that place. Awesome scenery everywhere. I was stunned and a bit bummed I didn't bring my bike with me.
If I were to have to chose your three options, I'd still chose #1. I'd also veer off route in Michigan and go into the Keweenaw Peninsula at least into the Porcupine Mountains and see Presque Isle Falls (getting to the falls could be a 50-70 mile day if you aren't camping). If time allowed, I'd go all the way to Copper Harbor. I'd head south and catch up with the route again near Crystal Falls and head for Escanaba. The scenery in the Keweenaw would have held me over through that rough patch from Crystal Falls to Escanaba.
If I didn't get detailed enough
and you want more info feel free to give me a shout.