Sportsman’s Warehouse had a good price on the basic Colt M4 Carbine 22LR at $459.99 last week so I picked one up. Gave it a lot of thought because the S&W M&P15-22 is tempting and was on sale at Sports Authority last week for $399.99. And Ruger and SIG have AR style 22s as well. I have read about the problems of each rifle and finally had to go with the Colt because it looks so much like a real M4 - even weighs about the same. Ok, we know it's not really a Colt but it does have the pony on the side. Umarex imports it and Walther of Germany makes it. It has some warts just like other 22LR solutions for the AR but overall I think it's made fairly well. I do have a real Colt Series 70 45ACP so at least do have the real thing but this .22 is pretty good. I finally got to fire it today and it functioned 100% with Federal 550 Value Pack from Wal-Mart, about 150 rounds. As expected, it didn't do as well with Remington Golden Bullet, failing to completely close the bolt every other time when a GB was the top round in the magazine. I noticed though the problem usually was when I manually released the bolt and once I got the bolt fully closed the rest in the magazine usually chambered and fired. In fact I tried a mag with 10 GBs and 5 Federals on top and all 15 fired with no issues. That didn't always happen but it did enough that it may be a way to use up GBs if you're desperate. Since I have other .22s that handle GB I'll just use Federal in the M4. I sighted in at 25 yards and had to crank the rear sight elevation knob as far down as it would go (under 6/3) to stay on the bullseye. I can see I'll need a taller front sight post and hope Umarex will send one. I also hope to buy the nice black dust cover spring they have and put it on my home brewed 5.56 AR which has a silver spring. Very nice touch that Walther used a black spring just like the military Colt M4s! Surprising how much better it looks black. Anyway, I'm pleased with the look, heft and function of the M4 .22 and know it was the right choice. There's so much bad that you read about them but I'm glad I chose it over the S&W and others. Highly recommended! Of course I don't have that many rounds down the bore yet but so far so good.