I own three machines ATM. One Dell Vostro 1500 from 2007, which is in storage right now because I don't need it no more. It served me well for 8 years. It has Arch Linux on it. It was my main right for 8 years, the last 3 years serving under soem kind of *nix system or another, I programmed in it every day, watched porn on it every day (after discovering porn), I watched videos on it every day, and just generally was the only thing I used for nearly 8 years.

One Macbook Pro 13" Retina from Late 2013 which I've acquired recently, which is what I use at work all day and what I use for non-gaming stuff at home. What I'm using to write this right now from work. Of course it has OS X on it which makes it very comfortable for programming.

And last a Mac Mini late 2011 which I use for gaming every day, especially the weekends of course. Gives me a constant 120 FPS on CSGO with minimal settings so it's pretty good since my monitor only has 60hz.

The way I kept them all synced is with my original dotfiles setup (copyright me). The dotfiles are on GitLab and the way I have it setup I have a folder for each OS and I just have a .symlinks file inside each of those folders which tells a script what place to symlink stuff to. If two files are identical on two OSs then the original is in one place and the "copy" is just a symlink to the original.