Can anyone who has hiked both give me an idea of how the Border Route Trail compares to trail on Isle Royale? We are planning to hike about 60 miles on IR- so the length is similar, but I am wondering if we can add a few more miles per day than we did while hiking the BRT. We are hoping to hike about to 14-15 miles per day. Does that sound appropriate?

You should definitely be able to get more mileage on IR. The trails will be more open, and easier to hike. Less mountain goat stuff to have to deal with. Of course, there will be way more people.
Bring a water bladder, as water filling locations are further apart.
When we hiked it, we really didn't have to worry about catching the boat back at the time that we told them we would be there. We got done a day early, and just caught the last boat that day instead. As long as they keep the numbers straight, that's all that they care about.

yep, what portagekeeper said.

I backpacked for two weeks on Isle Royale and it was amazing. The only time I had trouble finding a trail from from Feldtmann Lake to Siskiwit Bay. There was some major overgrowth from the tower to the bay, but still found my way just fine. From Feldtmann to Island Mine I didn't see a single person and had Siskiwit bay campsite all to myself. All told I covered 115 miles of hiking paths.

Rest of the island was a cakewalk. The hardest elevation gain was from the Greenstone Ridge to Lane Cove. Lane cove was beautiful though. That campsite and Little Todd Harbor were my favorites. If you get a chance to stay at either one, do so.

Aargh, just talking about that place makes me want to go back right now! Have a great time!

We hiked the Minong Trail and that was a lot of ups and downs. Different but similar to the BRT. Other trails wouldn't be as much elevation changes.
IR trails will be easier to find and will not have dead falls across the trail. No crawling on hands and knees. Ya can't bring your dog with you though.

Hey guys, thanks a lot for the input, I really appreciate it! Thanks for the tip about the water bladder. We have been pretty spoiled when hiking the BWCA trails, and rarely have to carry more than a liter of water.

My dog has been staying home on these longer trips, I have a fear of having to carry her out. Though I did not know they were not allowed.

I’m pretty sure it has to do with the transmission of Parvo or other diseases to the wolf population on the island.