I have not seen a great difference in the blades myself - in my experience what matters the most is that the blades are sharp. Everything else from gator to med lift, high lift ect has not mattered as much in my experience ensuring that they are sharpened and changed properly for the type of lawns you are mowing.
Example - if you are mowing any sand lot home prior to going to take care of a lush irrigated well fertilized lawn and not changing blades - you are doing yourself and your client a injustice as well as the fert and squirt guy who is putting good product down to make the lawn look good.
One of my biggest pet peeves is seeing a lawn with shredded blades of turf. You can tell from a distance who takes pride in there work and who does not right after they cut.
10% of your customers are 90% of the problem.
You may think the grass is GREENER on the other side, but if you take the time to water your own grass would be just as GREEN[/COLOR].