All the terminal thoughts mentioned above are good although there are still some weird BSD idiosyncrasies that you'll have to cope with (cp missing the link switch, find requiring an explicit target, etc) Ive also been using tmux and it makes the default terminal a bit more bearable.
Here are my biggest gripes thus far switching from Debian Jessie with KDE:
- The window management is laughably bad in OSX. I installed two extensions (divvy and cinch) to add window docking functionality which helps slightly but they are free only in that they pop up requests to pay every once in a while. Apparently there are some better extensions but they cost money and its my opinion that my workflow is my employers problem, not my monetary responsibility.
- Using virtual desktops on OSX after becoming accustomed to the Linux implementation sucks. Its is far less featured than KDE (at least out of the box) and a lot of the extensions to make it better seem to cost money. The desktop switching order is linear and it randomly changes the ordering on you while you are using it. There is also no concept of docking a window across desktops or opening a window on multiple. In fact, when you maximize a window it switches desktops on you.
- The firmware for the thunderbolt display is terrible. The USB ports keep shutting off randomly requiring you to unplug and replug the thunderbolt. Doing this totally screws up all your window sizes and placements. I generally have a full screen terminal on a virtual desktop and it causes it to underscan the window until I close and reopen it. Extremely irritating.
- I don't really like the focus management in OSX but this is more a minor UX irritation. My issue involves clicking on a text field inside a different application and instead of having the text field gain focus, the application gains focus but not the internal text field. Many a time have I entered text into the wrong entry field in the browser.
All this being said, Apple hardware is really excellent. Some of the peripherals are a little bit too 'designed' and not as functional but they are not unmanageable. The software needs some help and I still may switch to Linux in a VM at some point. For now I figure that I might as well give OSX a chance before I completely bail on it. The Apple fanboys would never let me hear the end of it.