We have very clear company procedures which are to follow the TCAS and not the controller, and I do follow the orders, they saved already my live once at least!
However, do not use the TCAS screen as a radar, target position are innacurate.
I have seen too much pilots using their screen for avoiding and or criticise the ATC...
The thing is to use the system as it should be used and the training and recurrent given actually will tell you exactly that.