I am disappointed by the dongle-for-everything design. As a photography teacher at a university and a landscape photographer, I would be looking at a minimum of three unavoidable dongles (no, a new cable wouldn't fix any of them - I'm not counting my own external drives, which I COULD re-case or re-cable). One of them is actually a DOUBLE dongle to replace a function built in to my current MBP... I'm defining a dongle as "anything that has an additional connection point to fail", and a double dongle as "an abomination that generates two additional connection points"
From least to most annoying:
1.) HDMI. For years, Apple used only non-standard video ports, then they finally got this one right on the Retina. We have a few old projectors around my university that DO require a VGA dongle, but I can usually beg a classroom that has an HDMI-capable projector for image review, because our decent-resolution projectors also tend to be HDMI compatible. Right now, I plug in a single cable with no extra connector to come loose - this machine would step me back to a few years ago, when the dongle inevitably came out while we looked at some poor student's images...
2.) USB. Even if I updated all my personal drives (I'm adept with a screwdriver, and re-casing my portables would only be a minor pain - desktop drives and the printer could be handled dongle-free with a new cable), I'd still have to use a dongle to read students' USB memory sticks! It will be several years before double-ended memory sticks with standard USB-A and USB-C are common, and longer still before they're ubiquitous. I suspect it'll be the best part of a decade before "freebie" memory sticks, which students love to hand me, are USB-C. I know double-ended memory sticks exist, but they're expensive enough that I don't want to hand them out when I may not get them back, and I certainly can't require students to hand them to ME...
3.) SD!!!! Not only is the SD reader missing, B+H doesn't even stock a small, direct connect USB-C reader (they do for Micro SD, but not full size SD). The options are either a larger cable-connected reader ( 2 extra connection points - card to reader to cable to computer) or a small USB 3 reader attached to a dongle (2 extra connection points - card to reader to dongle to computer). A double dongle for a daily function is COMPLETELY unacceptable. Yes, we'll probably see a compact USB-C reader for SD (and CF) before too long, bringing it down to a single dongle, but it'll be a hard to get reader for a while - carry a backup unless you're shooting in NYC on a day that B+H is open. Conventional USB SD card readers are drugstore items, and it'll be a while until USB-C readers are.
I own the immediate previous model (bought refurbished a few months ago), and I have the same RAM, a CPU that is within 10%, a SSD that is as large as you can get on the new one without paying over $4000 (and I suspect OWC will do a 2 TB upgrade for my machine within 6 months, which I WOULD consider - the Samsung SSD exists). My GPU is 50% slower, and I'm missing some screen gamut, but I have a machine that works with everything. By the time of my NEXT Mac, I suspect USB-C will be more palatable, and I hope Apple reintroduces the card reader...