I like Castrol Syntec, just cause someone decided to play a practicle joke on my by draining my oil pan and knowing that I had just changed the oil a few months before and coming no where close to 3000 miles. I never thought to check the oil until driving with out any oil in the pan for atleast a week maybe more. I was driving it pretty hard too. (Not my R it was my Civic) any way it wasn't until the car cut off on me one day that I thought to check the ignition and oil etc etc. the Car has about 140kmiles on it so I was surprised as it had never given me a problem.
Anyway, the oil pan was bone dry and smoking. I checked the engine to see if there were any leaks etc etc and there ws nothing. I put 2 quarts of LUCAS Engine treatment and 2 quarts of Castrol Syntec and the problem was fixed. Not one problem from that 140k mile engine.

Funny thing I was told by a well known conspiracy theorist that ALL Synthetic oils were the same. Meaning developed from the same Lab etc etc. LOL I don't think you can go wrong with either to tell you the truth.