From my personal experience, having owned a facelifted E65 as well as an F02 in the past (when I was madly intoxicated with the BMW brand) with the bulletproof N52 IL6, I can confidently attest that the IL6 purrs like a contented kitty cat on highways and there's hardly ANY engine vibration to be felt in the cabin. It's really that good. I personally skipped the N54 iteration because of the bad publicity surrounding the HPFP failure, and went straight to an M6 with the S63 engine. I sold that car for a massive loss because the engine ran too hot and was guzzling engine oil like it was going out of fashion, in Singapore's city driving climate. Then, the BMW noses got bigger and bigger and the design language got weirder and weirder, and I jumped onto the Porsche bandwagon - and that was it.

In my opinion, the E92 and even the F-series (apart from the bland as tap water F10, sorry fanboys) have perhaps the most beautiful design lines of any modern BMW.

You can't go wrong with either choice, bro.

Good luck!