not sure what you are saying. if you are talking about a shaft driven atv like a honda vs say a belt driven polaris? depends on who you talk too. also depends on what you do. if you trail ride and need to do work then both will be fine. both have their pros and cons. shaft drive transmissions normally are setup that there are shift points. even the automatic ones. the belt drives normally hold the atv in their power band. I say drive each and see which one you like.
unless you use high range when you should be using low range it should last a good while. the biggest problem is people use them in high range and pull too big of things with them in hi when no matter what you should be in low. power does not make up for gearing. another thing that happens is people go running through deep water. above the tires but below the racks and depending on where the intake and exhaust for the belt drive system is you will get water in there. that can cause a belt to fail also. but generally you take care of any quad and it will take care of you.
i have a 700 sportsman and as long as i ride like i have some common sense, it wont tear up belts. when i start getting stupid, it eats them up. normal riding, the belt will last longer than you need it to.
belt drive should be ok if your not going to be abusing it to much or swamping it in a lot of mud i had a polaris with a belt drive and after going through some soupy mud i noticedsliping i have a shaft drive now and dont have that problem