Which do you like better, the zero dirt or the stealth?
I like the stealth better. But it's fresh & new to me so keep that in mind. Also, I am riding it for exercise, so I get out on it a lot more often. And for exercise, it is superb, it really is. Get as much burn as you want, and you can go far away or ride any area. Legs are noodles after a ride.
I get a lot more farting around time while riding. So far I can ride as long as I want, and as fast or slow. I ride on any path I want, only going on the street when I ride at speed. Just like back when I was a kid, I find little things to jump or bunny hop. Too heavy to huck, but it doesn't take much of a bump to launch off. Riding off-road is when you notice the relatively low power. You have to ride in a different style, keeping momentum and avoiding squaring off turns.
With the zero you have more power, especially with a peak of at least 20 HP, which lets it be ridden like a dirt bike. The problem for me is that I don't get a lot of time on the seat. Always less than an hour. So I get frustrated if I have trailered to a riding area, and don't get enough riding. When riding local, it is always high speed on the street because it isn't something you can get away with on the sidewalk.
Since I have been riding the stealth I have been able to explore many more areas than I ever have with the zero. Mitigating the power by pedaling gives me a ton more range at the lower speeds. The dash is much better at calculating range because it measures the discharge. I would like to get a similar dash computer on the zero because range is currently very difficult to figure out.