I went .223 for the same obvious reasons already mentioned. I also like the .220 Swift, but barrel burn out is a consideration if you shootquite often....and ammo isn't particularly common. I've also heard of the downrange energy/knockdown problems of the .204. I noticed no one mentioned the .243, or even the 6mm Rem (.244)...which is slowly making a resounding comeback. Somewhat close to the quarter bore you already have...but very versatile nonetheless. The .222 had it's day, but nothing is gained in that cartridge that the .223 and .222 Rem Mag don't already handle better.

Nobodyshould give a rat's a$$ what I think, but this is how I'd rate them:

.223
.22-250
.222
.204

Good luck, anyway.