Thats true that you can't race the stock engine in the matrix, but at the club level that probably won't be a problem but I would check with the track director first.

Out here, they had a rule for the race series that if you were running the stock engine that came with the buggy, it was legal. You just couldn't put in some aftermarket .26 or whatever engine.

I would say the Matrix for the money is a pretty good deal. If you don't need motor, electronics, etc. they do have an ARR kit for around 290 you can purchase. For me, I figure if you can get the vehicle for 400 shipped. Sell the radio and engine, you probably work out better that way. The servos stock also have alot of torque for the money, 144oz with .18 transit.

As for durability versus a modded maxx I am not sure. It really depends on how much trouble you are having with your maxx. I would say that based on what I read, most of the 1/8 scale buggies seem to take abuse well. Only one I heard anything bad about plastics wise was the Hot Bodies buggies, but that may have just been that particular person.