First of all: thanks to the amazing team behind Kirby! You've done a fantastic job!
I decided to move our website (alexundberni.com) from koken to Kirby to get a bit more lightweight and to support two languages - finally allowing me to have English as an option! It only took me a couple of days and it really was an absolute breeze! The site feels a lot snappier and compact now - before things were sluggish and slow - and I really couldn't be any happier. Yay! Kirby is an absolute pleasure to work with!
I'm using Kirby with the excellent HTML5 Video and HTML5 Audio Plugins by Thomas Fanninger, the site is cached using memcached (Kirby made this easy as hell), everything runs smoothly, I finally have translated content (and not just German), I can serve alternate videos where I have English versions or just serve subtitles where I don't, etc. etc. etc. in short: it's fantastic! Cheers!