Having done both, I definitely do not agree that Spartan Races are not as hard. I think TM is more challenging mentally...will you jump into ice water/will you run through live wires, but not as challenging physically, especially since they emphasize the team aspect. With a Spartan Race, particularly the competitive heats, you do most of the obstacles by yourself (although I have occasionally had help) and if you do not complete an obstacle, you must do a 30 burpee penalty before you move on. 30 burpees are pretty easy when you just try to do them, but to do 30 in the middle of an 8-10 mile race is a whole other ball game, especially when you are watching your competitors pass you by while you are finishing them! When we did TM, there were tons of people just sort of walking, joking, etc...which is fine, but the fact that Spartan is a race just adds another dimension and another level of difficulty, KWIM? The obstacles are pretty difficult as well....for example, the 4 mile Spartan Sprint I did took 1:20, and I was the 3rd female to finish. Even though it was a "short" race, it took almost 3 times as long as other short races, such as Warrior Dash, etc....Anyway, that's just my $0.2!