I think each manufacturer has a little different approach to pricing on snow checks vs. closeouts. If you are basing on price alone, leftover or season closeouts will always have the better pricing. I think Doo is the best about clearing out excess inventory mid/late-season by offering good discounts coupled with lower cost financing options. However, the Polaris hands down has the best spring ordering program thru their customization. Buying the 2019 Summit X, you can pick one color, bright red. This maybe OK with some, but if I was ordering my sled, I'd appreciate a few color options. Polaris on the other hand, will have many base colors to choose from and special customization/combination of colors for rails, tunnels, spindles, better shocks, handlebars, windshield, GPS gauge, etc. Each manufacturer also seems to always offer an extended warranty at little to no additional cost with spring ordered and there is some value there for both the original purchaser and a future buyer; spring ordered models typically seem to carry a higher resale, but also suffer the greatest depreciation of all as well.
I have never snow checked but have never really shopped for one. The idea of buying new or even putting money down in the spring is a tough pill for me to swallow. To me, if you want the benefits of a latest and greatest sled, but can forgo the bells and whistles, then buying a leftover is best.