If a new rifle is in the works, I'd go with a 204, as it will perform right alongside the 22-250, and have less drop, less wind deflection. But know going in that the brass and bullets will be a tad more in price until supply catches up with demand, as it's still relatively new.
Check out the ongoing discussion on the reloading forum here on the 223 vs. the 204, and you'll have an information overload.
Basically though, the 204 will outperform the 22-250 and use less powder doing it, albeit with lighter bullets. I own and shoot both calibers, and prefer the 204.
For all the information you ever wanted on the 204, check out
www.rugerhunting.com/204 There is a forum there with previous posts that cover your exact question. Good luck on the project.