I have used silicon brake fluid, and know plenty of other people who have, for many years. I know no-one who has had any problems with it at all. I have read that it has slightly less lubricative properties, but I don't know what that really means. If it is 1% worse for example, and 50% worse would still be OK, then it makes no difference. We have no real data other than hearsay and peoples personal opinions to work with, and I have found this source of information usually to be wrong! Do you think you could legally use it on the road if, for example, there were lots of cases of it jamming servo's and brakes not coming off? I suspect not. It is commonly used in the USA, and if it is good for their safety and testing requirements, who am I to argue!