I'm running a prototype of Brents on my bike. Yes, it does flex with the steering, but the total arc of the steering head can't be much more than 90 deg, so 45 deg each way.... and because the line is so long, that bend is soaked up by probably a foot of the line, so there is not severe bending going on. I have the BP one also, and honestly still haven't decided which to keep on there. I am/was running Brent's as a favor to him to sort of smoke test it, give feedback etc. Especially on the install.
