Ive gone to the demo rides for the past 2 years. How far you ride is going to depend on the snow conditions.
I go the demo rides they have on Lake Minocqua in Minocqua, WI. Last winter snow was kinda minimal and temps were warm, so we rode about 2 miles on the lake and about 1 mile on the trail.
This winter we had good snow and cold temps, so the demo ride was about 4 miles. Thats plenty of time to get a feel for a sled, IMO.
They usually have a pretty wide range of sleds. This year they had 5 Apexs, a Nytro, a RS Venture, and a couple of Vectors.
This past winter they made a new rule that limited each person to 1 demo ride per day. However, they stop about halfway through the demo ride and give everyone the opportunity to switch sleds. That way, if you are trying to decide between a couple of different sleds you get the chance to try both sleds.
I dont think that Yamaha is letting anyone other than dealers demo ride the Phazer this winter, but you can bet you will be able to try one out next winter.
Im planning on getting a Phazer, but I want to demo ride one before I plunk down $7000 on one. I will be at the Minocqua demo rides next winter, you can bet on that.