I like the Dunlop 756 rear. I didn't like the 756 dunlop front because the side nobs chunked off before I was ready to change the tire. I have a 773 and it is much better. I've been trying to keep two tires in rotation. I put my old tire on if I'm going to practice/trail ride. I race my rear tire once then flip it for the next race. I race four enduro's per tire, flipping it twice. If I have a tough race/rock run I will run my practice tire. The right air pressure makes a bigger difference to me then the sharpness of the knobs or the length. If the terrain is soft then the sharpness matters to me. If it is sand then the length makers to me. If it is rocky then only air pressure matters. If it is muddy in any of these conditions then I want sharp, long knobs, with a good spread to fling the mud. I've spent money on good tire irons and have just accepted that I must change my tire almost weekly to save money.