From my standpoint, the advantages of electric over nitrous right now were numerous. First of all, it's cheap to find a good used electric car for $100 - $150 and perfect for a noob like me. I've never owned an r/c car and I really just wanted something cheap to start with. If I crash it I can fix it pretty easily and I don't have to fiddle with too many adjustments, worry about fuel and storing it or any of that. Plus I can race on an indoor track that's about a mile from my house and the car is quiet so I can run it in my drive, in my garage or up and down the street.
Disadvantage is that it's not as fast as nitrous and you have to wait around to charge up batteries whereas with nitrous you can just gas and go. The other thing is with electric you notice the car gradually getting slower as the batteries start dying.
Overall I'm very pleased I decided to start with electric, I've got a lot to learn and I think it's a good place to start.
Hope that helps.