I heard that they might not be as happy with some of the RR engines as they portray? I suspect it might be a little bit of a gimmick for lack of a better word. Does anyone have any insight? Maybe it's just a rumour, maybe not, i don't know.
What's clear though is that there are a few very good engine manufacturers, so I'd be suprised if the RR was outstanding in all areas, there's probably a trade off as with everything else in this business...