BTW & FYI the 284 Win is NOT "based on the .308 Win". The 284 Win has a rebated rim(.473) which is the same as a .308 while the case is larger ahead of the extractor groove.
The 30AR was born a loser and is destined to be an orphan in the near future regardless of it's attributes(if it has any). If you really need/want a .308, get an AR10.
The .223 is a VERY marginal deer round and contributes to many wounded and lost animals yearly. Yes, it WILL kill a deer and I started several kids out with it but that doesn't make it a good deer cartridge. A Ford Ranger will pull a fairly big trailer some of the time but, sooner or later, you're going to wish you had more weight and horsepower.