I think it depends on how your doing it. We are having a normal plated meal but then were thinking of having a taco truck come at the end of the reception for late night munchies!
Sounds like a great idea. We are looking into having an ice cream truck at ours.
I went to a wedding with a food truck. The food was excellent and it is a fun idea, but it was hard for the food truck to keep up with the number of guests, so people ended up hovering and waiting for more food to come out. You may want to consider whether the food truck will have the capabilities to keep up with your guests.