I have the nikon M-223, 1-4, and I works great for fast shots out to 300. It's not for pin-point accuracy, but it gets'm on target! The glass is clear and the turrets work great, but I'm not so happy with the reticle I picked. They have a single dot point-blank range and a bullet drop reticle. I picked the bullet drop, oops!. The 223 ballistics are so flat out to 300 that the hash marks are too close and too fine to pick up quickly. Wish I would have gone with a dot and used a combat zero, then just hold over or under (like you do with open sights), or if I have the time use the turret adjustments.
I also have the Primary Arms 1-6 with the 300 blackout reticle and like the magnification range and apparent build quality. The reticle seems busy and too complicated for a low tech guy like me! I can't say how it works because it hasn't made it to the range yet
If you want to try the 45 offset sights check out the eBay cheapie for $20. They had a sale with free shipping, I was tired, might have had a beer or three when I ordered.. anyway the point is the build quality is amazing for the price point. Another disclaimer; I have only played with these at my bench and have not used them at the range, but don't see any problem with them for an occasional close up shot. (In my defense I haven't been to the range in a while because it has been hellishly hot here and I'm not the A-man - been a lot busy too)