Many bigger cities seem to actually be surprisingly lacking on viable (and legal) landing sites for helicopters... Trust me, I've tried.
You may not be exhausted but sitting stationary for 7 hours just to get dinner doesn't seem like such a fun thought, even in first class. (The novelty wears off very quickly)
Seriously though, you're forgetting timezones. Hop on the jet at 11am NYC time and be in London at 7:30pm London time. Leave London at midnight and be back in NYC at 10:30pm NYC time. You're not going to be exhausted from travel because it's first class all the way and you don't even need to pack bags.