In my time in the Army I used both the M-68 and the EOTECH. The Eotech gave a better field of view and it allowed multiple target tracking. On my M&P 15, I have a Trijicon Tri-power, I have not used it as of yet though.
Trijicon Accupoint 1.25-4x TR21R, or the new true 1x version that is supposed to be out very soon. Great FOV, awesome glass, miles of eye relief, American made - easily the best scope at that price point (~$575).
How do you define "tactical scope"? More directly, for what will you be using your rifle?
Shooting at moving targets at 100 yards and less will suggest a different optics solution than shooting precision targets at longer rangers. Some optics (like low power variables) work pretty well for both.
I agree with Rhino. Considering the 16"bbl, your overall range is limited. When you get into high powered scopes, parallax is a real issue and one you really don't need to deal with - esp with a .223 and a short bbl.
Tactical is as tactical does. If you want magnification, check out something like a 1x4, or 1.5-5x Leupold, the 1.25-4x Trijicon, if you have the $$$ a 3.5 or 4x Trijicon ACOG. Yet another option is an Aimpoint ML2 with 3x magnifier, or a EoTech with magnifier.
If it were me, I'd keep the max power at 5 or under regardless of brand.