Lots of retailers still have the 2015 MBP 15" at their original prices, some cheaper, and not Apples new inflated price. With the huge jump in price on 2016 models. This is now a serious consideration for me, even though they're 18 months old. From a longevity, future proofing, benchmarking perspective. How much difference do people think they'll be? Is the newer processor, design, now dedicated graphics, and Touch Bar really worth an extra £800?