I've used Windows from 1998 to 2014 (98, XP, 7) and I loved it.
In 2014, I bought a Macbook Air and I loved it more. Still, I don't think there's much difference in terms of productivity for me, but Mac gives me the "I'm a developer, duh" feeling. :)
Even though I'm not an experienced programmer, here's my setup : Macbook Air (OS X Yosemite) on the left for development, 17" external on the right for documentation. It really helps.
Sometimes I am thinking of getting a large third monitor for IDE** and an external keyboard (a mechanical one like Razer Chroma**), but I give up too quickly.
I use MAMP for development environment (phpMyAdmin & PHP).
** Like this one, you can even use it vertically : http://www.amazon.com/Dell-UltraSharp-U2312HM-IPS-Monitor/dp/B005LN1JEC
**Razer Chroma : https://www.youtube.com/watch?v=0VRK_bsE6nw