I think it was two main things, the feel of the 275 RE-71Rs , and this seems to be agreed upon by all who have tried them, is amazingly direct. No squirm like I experienced in both the Rival and the Falkens. Part of that feel may have been the 275 on a 10.5 inch rim vs the Rival 315 on a 10.5 inch rim, but it may also just be the tires personality. The other reason is compound. The RE71R is softer, even though both are rated at 200 TW. I see more wear on the RE71R than the Rival. Oh and both these tires felt pretty darn good hot or cold...