Thanks for the answers.
The BSx2 one10 Response is quite new and I have read that some have problems with it.
Really wanting a brushless servo, counting out the RSx One 10, I bought the "old" well tested Futaba BLS551 instead.
The BLS551 is now replaces with a newer version (571 or something I guess), which is capable of running HV, but as I do not run HV in my touring car, the BLS551 will do fine.