Glueball, I wouldn't trust the accuracy of the TCAS readout to use it to provide your own lateral separation.
From my side, the tragic events 2 years ago only re-inforced that what we are taught is 100% correct, and that following the RA as apposed to my instructions is what pilots should do. I will issue the vectors to avoid even further, but no reference to height will be mentioned.
To refer to Heathrow Directors post, I have also seen the consequences of when TCAS gets it wrong, that when vertical separation existed TCAS took over and eroded it. Even in these circumstances I would expect pilots to follow the TCAS call, and would not intervene with vertical instructions.
Skyhawk1, I can assure you that many lessons have been learnt following this accident. In the world of ATC its one of those events that is now rarely mentioned but is often in the mind, our thoughts always go out to those that were in the air as well as those that were on the ground and hope it will never happen again.