I love my .17s. They have been very dependable on fox and cats. Coyotes can be a question on some occasions. I have always been able to retrieve them, but some of the bigger dogs have run a ways on occasion, especially if I shot them on the shoulder instead of behind it.
I went over to the 204, simply because there were more factory load options out there. The 32 grain loads and lighter dont seem much different from my 17 loads. The 40's or a fringe hit look a lot like a 22-250 got into them though.
If you have an accurate 17, keep it and enjoy it!