> Anecdote: a family member and software dev just bought the latest macbook pro coming from about an 8 year old macbook pro. Apparently he doesn't perceive much real world performance difference between the 2 machines. He said single core synthetic benchmarks were higher, but not by much.

Honestly, I think this speaks to the quality of Apple's hardware and engineering (8 years ago), combined with the lack of serious improvement from Intel lately.

That said, one thing I've noticed when doing IT and desktop support is that, unless someone's hardware is woefully inadequate, they won't notice a huge change going from slower to faster, but they will notice faster to slower after they've been using it for a week or two.