I just came back from Superior Circle tour - I did it clock-wise, so I was in TB 2 days ago... Weather is unpredictable due to the water always being cold.
I liked Eagle Canyon Adventures as a stop-over, but know it's a dirt/gravel road leading up to it - couple of kilometers, not bad, I did it on sport-touring...
Watch for OPP... they are everywhere and aggressive. Feels like a bit of a shame - entire way around the lake you get no BS, then in that area, they are onto everyone like stink on ****... Really nice way to treat tourists (I knew about this so I took it easy).
Watch yous gas - area from Terry Fox monument going towards Wawa is under construction, and there is a long(ish) stretch of no gas stations.
Speaking of Monument, I had run-in with a deer on the road to monument (during daylight)... it is a nice little road, easy to get carried away.
Accommodations are still expensive on Canadian side - in Soo, there are cheap (very basic) motels. I think Pine Grove is $55/night. Bring bug spray, Soo was pretty bad.
Regarding recommendations on what to see; it depends on what you like - I like nature and native themes - There is so much to see along the way, I could spend a month in that area. Shane's write-up is good too.
Day to Soo and a day to TB - then back, it doesn't give you a lot of time for exploring - plan it carefully.
Have a great time if you decide to go!