I read the Snowgoer article, it would seem SLS has addressed all the issues. The front spindles have brakes that tie into the existing breaking system. The front spindles also have adjustable geometry so the handling can be dialed in to your preferences. There is a radiator in the tunnel/ahead of the rear wheel for cooling. There is a control pod that goes on the LH handlebar for turn signals, horn, etc. The current kit uses a chain drive, they are coming out with a shaftdrive model to eliminate the long chain. The kit is designed to be realtively easy to switch back and forth once the components are installed the initial time. It would seem the hardest part will be pulling the driveshaft so that the track can be removed in the spring/reinstalled in the fall.
$6000 seems like a lot, but, if you have a Yamaha or other 4S sled, you know the engine is good for the miles, and this effectively triples your riding season from one to three for a lot less $$$ than buying a spyder (the spyder lists for $14K and I have seen some new carryovers locally for $12K, quite a bit more than $6K).
One concern not mentioned is emissions. Probably not an issue in the midwest but I would imagine you could not register one of these in CA or the Northeast where the emissions regs are tougher.
I like the idea, and I hope it is a successful endeavor for SLS.
