I use Lenovo P50 - 64GB RAM, 4K display, nice keyboard, card reader, Ethernet port(!), and Quadro M2000. Especially nice thing about is that it supports 2 SSDs

I use Lenovo P50 - 64GB RAM, 4K display, nice keyboard, card reader, Ethernet port(!), and Quadro M2000. Especially nice thing about is that it supports 2 SSDs + 2.5" harddrive (all easily removable and upgradable). This means I can keep my Linux installation completely separate from Windows on separate drive without having to partition anything. All these at a fraction of price. I can keep old MBP around for iOS stuff but these days much of the computer vision and deep learning development happens in Linux so configuration like about works great as main machine.