I have some fast varmint guns, including a .17 Rem. The .204 is always my first choice of guns when the shot counts. Stock Tikka that shoots MOA. Very fur friendly, crazy accurate, fairly quiet, excellent in the wind.
.17 REMINGTON is fun too, very fur friendly but a nightmare in a slight breeze.
I have been doing some penetrated tests on some varmint calibers, on a 1/2" steel plate. The .204 is pretty amazing for a tiny pill, right behind the .220 Swift.