afatsuoM you are not the only person that suffers from BR failure,and there have been many long discussions about them,some people like them and a lot loathe them.....there's even a poll a few pages back.

Your less likely to fail pulling off a BR using the D-Pad,and that's the only reason why a lot of players use it.
I asked Mad-Ice what his technique was and he replied that he just rubbed his thumb quickly side to side across the D-Pad.
Seems to work,but there is a % of failure even doing that,I've also found that it's easier to BR using different,but supposedly identical controllers,why I don't know.
You have the same problem with the sticks,except more so I find,your going to have a % of failure no matter what,how high that % is depends solely on changing your technique and practice,there's no magic/easy way of doing them,I've looked.

Unfortunately BR's are now ingrained into wipeout,they are a PITA ,and unless by some miracle SL decides to give us and option to remap the control method of doing them,then your be stuck in the same boat as the rest of us.