My first sled was a Yamaha 292, I agree, cheap oil all day, no issues.
Newer machines perform better with the temperature stability of a quality lubricant - really better for them in the long run.
I'm not necessarily sold on Arctic Cat or Polaris Oil, but I think it is important to use a high quality lubricant.
I usually wrench on my own stuff... Boat motors, trailer bearings, snowmobiles, snow blower etc.
Last weekend a buddy and I got together and went through our sleds - been doing it for years. I remember a couple of years ago my buddies neighbor joined us. In addition to chain case oil, plugs, slides, grease fittings, and belt stuff, we clean the power exhaust valves.
I use Polaris Oil, buddy's neighbor used whatever he used, not sure. At any rate, his valves were really sooted up. Spent quite a bit of time cleaning them so they floated up and down nice and easy the way that they are supposed too. Mine were so clean last year, I didn't even pull them out this year.
Two strokes "burn" oil, and can leave ash and other undesirable deposits behind. When your flying across the lake your burning quite a bit of oil, and you want to ensure that it is burning cleanly. TCW-3 is a minimum rating to meet EPA regs., and satisfy lubrication requirements. Higher quality oil is also TCW-3 rated but uses a better basestock and typically performs better under higher temperatures. The better the temperature stability, the higher the cost.
Amsoil works good as does Polaris, Arctic Cat, Ski Doo, etc...
Whatever you use, just make sure it is high quality stuff that doesn't leave a bunch of gunk behind when it's burning.
Have fun with the new sleds! Shaping up to be a good season!