Considering the new 15"...( 13" is USELESS) ...Macbook Pro starts at over $2,500 with the necessary i7 CPU, ( forget i5).....you would be WAY better served to go with a powerful Windows gaming laptop for HALF that price from a company like Asus,or, others. If money is no object and you MUST go Apple, then, there are SOME pros and some cons.
1. Pro - has Thunderbolt, for hi-speed EXPENSIVE external storage, or, for Hi -res external monitor....however, MY 2 year old Asus laptop HAS a "thunderbolt" port , TOO...which I use to drive a hi-res monitor.
Con - though NVidia 750m 2GB GPU is adequate for much of the CUDA accelerated operations, newer Windows laptops have more advanced 800 and 900 series GPUs with far more video memory...for HALF the price !
2. Pro - PPro and AE runs best with Windows 8.1
Con - Mac operating system in the recent past has had issues and hiccups vs. Windows in running Premiere Pro....I'm not sure if all that has been fixed at this time.
3. Pro - newest mac book pro uses PCI SSD storage...amazing transfer speed of data !.....however, a 1TB flavor of this costs an additional $1,000
Con - not sure of the maximum amount of system memory that can be installed in MBOOK PRO..."Apple Chat" guy says 16GB.....you need at least 24 GB...better to have 32 GB for best operation. Also, some Windows gaming laptops offer internal RAID options for high speed storage ,or, at least two internal HDD bays for SSDs.
In addition : The "Mercury Playback Engine" is a feature of Premiere pro which allows for the "acceleration" of certain effects and operations on the timeline...in many cases eliminating the the need to "render previews" to see what you are doing. When coupled with a capable NVidia GPU, this acceleration can produce a TEN TIMES IMPROVEMENT in processing the effects,or, operations, ( like "scaling" and resolution conversions ) using the NVidia ONLY CUDA technology.
In summary, the 16GB memory limit , the lower level NVidia mobile GPU, and EXCRUCIATING HIGH PRICE all tip the scales for me to say : NOOOOOO !!!!!......DON'T DO IT !!!
IF a laptop is a MUST.....go with a Windows gaming rig and READ as much as you can first. If a desktop is a possible solution, you can get WAY better performance than a laptop...especially with today's Haswell E CPUs and the X99 motherboards.
I would wait a little bit for all the machines to hit the market which have the NEW " NVMe" PCI SSDs in them, or, build your own on a motherboard which will NATIVELY have that feature.
Good Luck !