As I previously posted I have riden them for 3k miles of commuting, riding with groups and even a century. They have performed great for flats(only a handfull in that time) and the ride quality is excelent they are heavier, but not noticably. For a short period of time I rode wtb alteranasaurus and they were slower for sure. everyone that rides them has commented on the good ride quality. I have just recently switched t panaracer t-serv 28's and other than the gear ratiochange I have not noticed a huge change in speed or ease of pushing the t-servs are just a harder ride.