Castrol 5w40 isnt the most modern oil, but it gets the job done. Not sure I'd run it 10k, more like 7.5k. I'm taking the car to the dealer for the first time to get my 20k done this weekend. I'll take a "free" OC, but will probably only run it 7.5, like I said.
I REALLY like the way the car sounds and feels with M1. GC was fine too, but I like the TBN reserve on the M1.