Well.............. with all the 5.56 critic's and alleged lack of stopping power, the 6.8 SPC might be something worth looking into with the new bolt carrier design. If the 5.56 is having all the issues reported, it boggles the mind, why the Military continues to use it? Course, with all the AR's in service, it will always be a good idea to have one. I have also given thought to a different .308 rifle, as I have 2 Springfield's.
If we go into dream weapon's, The Barrett and several other brand's in .50 BMG would be interesting to play with of course, that's big money, and something I personally can't afford