The difference in performance between a recent laptop and a 2012 era one is marginal, but the difference in power consumption is considerable. My 2012 Asus has

The difference in performance between a recent laptop and a 2012 era one is marginal, but the difference in power consumption is considerable. My 2012 Asus has a i5-2410M, which has a passmark score of 3154 and a TDP of 35W. My recently purchased Dell XPS13 has a i5-6200U, which has a passmark score of 3926 and a TDP 15W. A 25% improvement in raw power, but a 190% improvement (almost a factor of 3!) in performance per watt. The reality is both are fine for day to day browsing. The real difference is that the power difference means the Dell has a smaller battery, so can be thinner and lighter. Given that I use my laptop plugged in and with a monitor 99% of the time, there's no real reason to upgrade.