You're comparing the mini to laptops, which is a fair comparison.This is just 1 year of age difference we're talking about so that 3 years is very exaggerated.
Actually three years ago, quad core machines were available with discrete graphics, which would outperform today's mini. So my earlier statement that the mini is comparable to the fastest of three years ago, is not really true. Nevertheless, today's mini is plenty powerful enough for most anything you throw at it, except games — unless you're the impatient type.