Hmmm...well I live near 74 St station, but in fact I do walk up into the 80s for a number of reasons. To visit people who live there, to patronize stores and restaurants located there. It's hardly true that I am cut off from that part of the neighborhood because I live in the mid-70s.
It's a great advantage to be closer to the 5 train lines at the 74th St. transit hub vs just being close to the train at 82nd St. I don't see how you can argue that point. And the idea that being in the 70s is noisier and the streets are less clean--well, it's just not true, and you can walk the blocks to see for yourself. It's dirty and noisy on Roosevelt, all along Roosevelt, but north of 37th, the streets are quiet and pretty in the 70s.
We love where we are, because it's a six-seven minute walk to that station, while also being within a block or three of everything we need: two large supermarkets, several fruit/veg stores, the post office, several dry cleaners, a cobbler, a 24-hour Duane Reade and many other pharmacies, a few late-night bodegas, a mailing and package store, E77, Table Wine, Farine's.
Speaking of which, I have to laugh at the poster here who predicted doom for Farine's because, the poster said, it was in the wrong location for the type of business it is. It seems to be doing extremely well with all neighborhood constituencies: I walk by it often on my way to the station, and it is always busy, sometimes jammed with customers. The food (not to mention the sweets) is excellent, and people seem to be responding to that.
When we were looking to move to JH, we also weighed the 80s vs the 70s and came down solidly on the side of the 70s even though we did see some nice buildings and apartments in the 80s.