Feeling like experimenting a few months back, I swapped some 2 1/2 year old LaBellas for a set of DR Flats and BOY was that a jump in tension. I've acclimated to them now and I don't mind quite as much, but I think I'm going to switch back to LaBellas or go for some TIs when I get tired of these DRs. I love the DR rounds but these flats are pretty high tension.