You have all the big game rifles covered.... I'd keep a .270, if I felt the need for something bigger. I've owned and hunted two different 30-06's and simply like the .270 a lot better. It'll kill anything an 06' will and is more pleasant to shoot.
What I would do if I were in your shoes, is buy a good fast twist .223.
Scope it, shoot it, hunt it..... it'll soon be your absolute favorite rifle.
