My husband used to work for a utility supplier for all of the big house building companies. His opinion is that most of the houses wont be standing in 100 years time. they are built to make money for the house builders, not to last. they are built by massive teams of builders who throw up hundres of houses a year in a production line fashion and often never see the finished product or the people that will live on them.
Regarding noise etc. the houses are build with as little brick as possible, so most internal walls will be non supporting (stud) and therefore they tend to be nosier.
Obviously if you are detached then its different, but honestly, if you slam a door it shakes the whole house.
I believe small scale developers, like snowflakes, are different kettle of fish, they still have a link to the house and see the projects throught from start to finish. I know quite a few of them, and whilst they are still in the game to make money, they do care about what they are building and what they are leaving behind, as it were.
That said they tend to be more energy efficient, can be well finished, maintenance bills will be lower and offer things like massive garages etc that you wont get in older houses.