In all fairness, I think it's tough for some of us to get a feel for the game in relationship to the Tribes we love when the majority of the movie takes place on that stadium map. It doesn't have a lot of skiing, and is far more quake-ish.
I also don't like the large number of trails. I don't think there need to be jet trails, just throw in a burst of flame at the appropriate locations. The flag trail isn't so bad, but when you throw in the flag trail with the jet trail, and all the weapon trails.. it becomes cluttered.
The disc speed looks good to me. The jetpack has a hell of a kick.. maybe that will just take some getting used to. The grappler looks awesome. It does exactly what I wanted it to do. When it was mentioned my first thought was "Batman the movie" where the car has something similar and it grapples a pole to swing it around. I'm glad to see that's what it does.
The movie doesn't really show a whole lot, except the abundance of trails, and how some of the weapons work. It does have some of the physics, but not a whole lot of skiing physics. It obviously wasn't that structured of a game, and even Tribes would look quake-ish at times when it's not structured.
All in all I think it was a good movie. Some of the complaints people have might be lessened with a map that more people can relate to as a Tribes style map. The stadium style maps look like a lot of fun, and I can't wait to try them, but in the context of Tribes I know that people are used to maps similar to the one that was glimpsed in some of the grappler stuff.