Your observation holds in desktop. In laptops, the thermals of the 14nm generation were horrible, essentially you have to deal with a whining fan or cpu throttling, or both. AMD's 4000 series has much improved upon this, and I assume that the latest 10nm Intel will be much better. Performance-wise I agree with you. Minor changes, probably more noticeable changes come from the massive adoption of fast SSDs (1-2GB/s).