I have a Craftsman 9HP walk-behind and a blower on my GT6500 26 hp garden tractor.
The walk-behind is OK, I suppose. It starts reliably, is very strong, and hasn't had any failures, except that the wind cab flopped into the muffler in a strong wind (probably over 40MPH) and melted a small hole. On the negative side, when going into deep snow, the snow over the top can plug the muffler and stall it, and the handle levers are stiff and get painful to hang on to after a while. This took 6.5 hours to do my driveway sufficiently to get a vehicle through even after the big 8-ft drifts had been history for a few days.
The snowblower on the tractor was a pleasure by comparison. No shifting, just press the hydrostatic pedal to an appropriate speed for the depth of the snow. After the wind had completely filled in the 1/4 mi driveway, it did in 1.5 hours what the walk-behind took forever to do. The drift-breaker would do what it was supposed to do, and you could back out and re-attack deep drifts for the overage, except for the real crazy drifts, which you needed to tunnel and knock down by hand.
The directional control on the Tractor's chute is superior to the one on the walk-behind and the flimsy plastic cab works better than I had expected - but it's not a comfortably heated room.
Complaints: The brackets for the Craftsman blower and the Craftsman front plow aren't compatible, making changeovers more involved than it needs to be. The reach for lifting and dropping the blower on the right handle can be such a long stretch that the kill switch on the seat gives you problems. It would be nice to have 4wheel drive, shaft-driven front pto, hydraulics instead of hand lifting, extra lights front and rear, liquid cooled engine, and a more efficient diesel, but that might affect the price a little