With regard to the life of the SM7 that we run now, at the front of the 4-day Majors events, most of the front runners are going through at least one set of stickers a weekend, sometimes two. Sure they can run many more heat cycles but you may be sacrificing a tenth here or there, and at the front, every tenth counts.
I absolutely agree that the Toyo is the cheaper tire to run, no question. The fall off per heat cycle is less than the Hoosier.
Interestingly, I prefer the RA1 as the rain tire as it is so sketchy compared to the H20 that you really have to grow a set if you want to go fast on the RA-1 in a monsoon, whereas with the H2O, pretty much everyone feels like God on that tire in the wet!. Furthermore that RA-1 pumps way less water, which means that if you are the following car, you can actually see where you are going, and get up to the bumper of the cars ahead, which is often not the case with the H20 on a really wet track, you are often driving blind behind the cars ahead of you as you get close to their bumper. Despite this, I suspect that most would prefer the H20 as the rain tire for the confidence it inspires.
However we got Zero trackside support from Toyo, lots of trackside support from Hoosier. Personally I can see the merits of both tires.