Remember also, that BMW recommends a whole host of other oils that also meet their LL-01 specification. One is never "required" to use Castrol products, they are only "recommended" And even more manufacturers claim to meet the specification, though they may not have BMWs tacit approval. The Castrol Syntec 0w-30 European Formula has BMWs approval, but it is NOT the "official" oil used or sold by BMW. It has not more relevance than any of the other oils approved by BMW, such as Mobil 1 0w-40.
I've simply found it easiest, and the least risk involved, to tell any new BMW owner to simply follow BMW's recommendations. While one can use whatever they like, most probably would want some justification for why...and then the discussion gets bogged down for pages and pages of opinion, technical data sheets, and even a little hocus pocus.
Factory M-Sport package with factory installed M-tech bumpers, factory Bluetooth, factory M-Audio 10" dual voice coil subs, Homelink, M5 rear stabilizer bar, H&R 15mm spacers, Bilstein B14 PSS coil overs, Stop Tech ss brake lines, Akebono Euro Ceramic brake pads, oem Brembo and Zimmerman rotors, Dinan Stage 1 software, Strong Strut front upper stress bar.