I couldn't justify the cost of a MBPro spec'd to the maximum SSD capability. I had a requirement for terabytes of VMs which not even the highest spec'd MBPro would solve, and even if it could all this great SSD performance would be wasted.
The solution was to work a little smarter and create a NAS out of my old Windows desktop PC. For travel I brought a 1TB Toshiba portable drive for about $50 which I use like a big USB stick.
Keeping my laptop "thin" in data seems to be working quite well for me, another bonus has been that all my other old laptops ('bout time I donated them) can also access the same data the same way.