I would look on the parts issue's,How much and how hard is it going to be to get parts.For you Tamiya fans,sometimes it's not easy to get parts in the States,I know you can mail order but it is still nice to go to your LHS and get the parts right now..
If your just bashing both cars should be just about be equal,If the street or parking lot has any pebbles they can damage a belt(I have had that happen)I also know that on some of the parts you buy from Tamiya they come on a parts tree and cost a bit more..but you do have "extra" parts..
I think on the parts issue I would give the nod to Associated,I think Associated has the best parts support in the hobby industry..For bashing I know what my choice would be..it starts with a T..