Having done LHR/NRT quite often in the last few years with both Virgin and BA, I think the service is pretty much the same with both carriers. The only real difference is that when Virgin screw up, they do it mightily!
Incidentally, for the much flaunted Virgin massages in upper class, I've only had about a 10% sucess rate in getting one despite being asked to be woken up if my turn came. My wife's sucess rate is about 15%, and she's got the Virgin gold card.
cur