About the 711s, I like them. I've used 712s before, and agree, they're terrible. The 711s are much cheaper, better in the wet, and handle better, IMO.

They however, are NOT a REAL performance tire, and you won't be happy if that's what you're expecting, but it's a good all around tire.

As for street mileage, I can't really tell you. MR2s EAT tires, fancy alignment or not, they eat rears. I get ~12,000 miles out of a set of rears, and ~20,000 out a set of fronts. On a mustang who doesn't drive super agreesively on the streets, and uses the 245, I think you should, at the VERY LEAST, equal your yokohamas in treadlife.