the XRS uses a double pump feature to go into reverse. try your mini t on the pavement without skidding the rear tires and see if it still goes into reverse. you will be able to see if it has brakes.
i dont have an XRS though, i have a Spy micro. i mainly run on pavement, and when i am off throttle and the truck is coasting to a stop, i press the trigger forward while the truck still has momentum. the rear wheels immediately kick into reverse and spin backwards slightly while the truck is still going forward. i know this is probably killing my transmission. so do you think if i change to forward only(hardly use it anyways), i will brake instead of going into reverse(it cant b/c its disabled)?