I will take your back in 20 over mine in 20 yrs. I honestly think I will be cripple be age 50 or so. I am not saying that sawing isnt easy either. Trust me I have had ton of shit sawed for me and I know it takes alot of hard work and alot of hours. But I still think in the long run that laying concrete down, finishing will has more body abuse then the sawing whether it be your hands from trowel finishing, your wrists from swirl finishing or just plain your back from being bent over all day pulling concrete with a 1 man 12' straight edge cause the idiot raking behind you doesnt know his head from a hole in ground.