The retina display MBP really is an great machine, if you are prepared to pay 2grand+ for a laptop.
2.5 times the resolution of 1080p, As light as the 13" model, As thin as the MB Air, dedicated graphics, full power mobile quadcore, 7 hours battery life, SSD, aluminium chassis and all the usual apple stuff (good keyboard, excellent trackpad, magnetic power connector, etc.)
Probably the best 15" laptop out there by a large margin, if you are prepared to pay for that.
As if other laptops could be repaired or upgraded easily. RAM and SSD are usually the only user replaceble parts and everything else are custom parts that cost shitloads of money on ebay.