Looking to get the kids a mid-size machine (possibly an Arctic Cat 150) and don't know much about them. I want something that the younger guy can grow into and that his sister can ride now and use for awhile. I have reservations with a chain driven atv (the A/C) as I thought all but the itty-bitty machines were shaft drive. Is this an issue today? (I ran an '83 chain-driven Big Red for years, but the chain was protected and covered--not so on the A/C, but I doubt the A/C would be roughed-up as much as the 'ole '83 has been.) Any opinions good/bad/indifferent regarding the chain-drive & atv?