The only other 100 miler I did was the Hampshire 100 & it was just brutal with very little good singletrack which made for a long, long day. In comparison, SM100 was just a blast for me. Was I fast? No but faster than I was in NH.
I’m any case @MI-XC mentioned Lumberjack 100. I did a little searching & that race does look really fun. I’m considering giving it a go next year on a singlespeed. I quit Hampshire roughly 70 miles in on my SS back in 2015 & ive regretted it ever since. If I have a shot left for a good 100 miler with only 1 gear, I think that’s it.