I can only comment on the xray and I have only had one brakage on this ( rear axal) and this is now a one piece unit so won't brake again. Works well out of the box with a set of associated 020 springs. I don't know anyone withba BMI but beleve they are good also. I don't have any particular brand loyalty with my 12ths and like to try different chassis. Was looking at v designs and top racing rebel next time maybe.