#Tee said:
the non sliding action dulls blades fast. i use my non slide 10in dewalt for rough cuts and rustic furniture.

. just hold out and never get the slider. you only live,use tools and build once.
Edge life is more a function of grind type, grind quality, type of carbide, tooth count, type of material being cut, volume of material being cut, cutting technique, tool set up, and cleanliness of the blade. If you decide to use an H-ATB grind to cut everything or start cutting wood with a TC grind you will get poor edge life . If you are running low quality blades you will toast edges quickly. Their carbide is often either too brittle or of poor quality and the grinds are imprecise. If you are running a tooth count that is too high for the material being cut the heat build up will dull the blade prematurely. If you are cutting very dense material with the wrong grind edge life will be shortened. If you are forcing a blade through a cut the additional heat generated will dull the blade quickly. If there is a mechanical problem with the saw that affects cutting it can shorten blade life. I recently retired my 10 yr old 716 for a new one because of excessive wear and flex in the trunnion. The extra slop caused a pinch on the right hand miter generating too much heat when making a cut. If you don't clean the pitch build up off the teeth cutting will generate excessive heat and it kills the edge.
I own 2 10" and one 12" sliding miter saws in addition to the fixed miter saw. I run premium quality industrial blades and use the correct blade and tooth count for the material being cut and the finish required. I obsessively keep my blades clean. My saws are routinely checked for setup problems and I go as far as tuning the blades to the arbor to minimize runout. The only difference in the edge life on tooling I run in any of my saws is based on cutting volume. I use the fixed miter saw a lot more so consequently the blades I prefer to use will require sharpening more often.