"Same as the axle setup with wheel hub pins to lock/unlock."
My current machine (Ariens 28" Deluxe) has an axle that is locked. To unlock it, you squeeze a lever on the handle bars. To release it, you let go of that lever. Sounds good, but the mechanism sticks. Other, more expensive machines this size and larger use their "Auto-Turn" feature with similar, mixed results.
My Dad has a 2007 vintage Ariens 28" with about a half dozen different features. His axles have pins which you switch around to lock or unlock the axle. He, however, has heated grips and a larger Tecumseh engine.A bunch of his controls are different as well.
I bought my current machine in the fall of 2011. Ariens has evolved their 28" machine extensively over the past decade alone. There are about dozen slight variations during that time ... maybe more.
My machine has the cast iron front axle. Dad has the aluminum one. I know the iron one is seen as a premium feature ... it's probably stiffer and more fatigue resistant.
I like the light on my machine ... not nearly a real headlight but it works enough and I have used my machine in the dead of night with no problems.