If you want speed, get a sled
Ditto.
Even if the theoretical top speed is "over 25 mph" the actual speed someone will be able to maintain over varied land conditions will be somewhat slower. I'd guess at least 25% slower.
My Snow Trac is set up to do a top speed of about 25, but if you think about it a car with a theoretical top speed of 125 is rarely pushed that hard and rarely pushed that hard for very long. Same is true with any of these snow machines. Push them at the limit for a long drive and you're going to stress something until it fails. Be it a hose, a belt, a gear or a track. Out on a smooth open farm field that is covered in snow a
FAST run is a lot of fun, but on a path the speeds drop pretty dramatically.