I guess the two things that remain are 1) being able to mess around with the Touch Force and have 5th generation processors and 2) having a computer that is exclusively for work.
As for 1) - It's a freaking trackpad and not some revolutionary technology breakthrough. As for the processor, how fast is fast enough? I don't see the justification there. #2 is subjective and only you can make that decision. But, if a trackpad is one of your primary motivators, I'd stick with whatcha got and not look back. As for size/weight, I go back to the days when a "portable computer" was the size of a suitcase. What does a 15" rMBP weigh, slightly north of 4 pounds? I think you can handle that.
-jeff