Ruger's AR 5.56.

Does anyone have one? Do you like it? How does it shoot?

Captain O,
If it helps you make a decision on whether to buy or not, I can only give you my honest opinion.
RUGER for me stands for the finest American quality gun making. I had an issue Mini Ruger in NI in 1972 for a short time, and the rifle gave valuable service and never faltered once.
Fast forward to 2016, I possess a 10-22/SR22 Ruger and can only again reiterate its reliability, with many many options for various furniture if you don't like what you have. It is a very flexible and versatile rifle even at that low calibre.
My advice is, if its right for you, buy it quick.

I have no personal experience with the AR 5.56, have bought Ruger firearms for 45 years. I still have my 1973 production 10-22, and have had numerous pistols and several Mini-14s and Mini-30s. All were great weapons, and worked perfectly. I would not hesitate to buy one.

I have held one and it sure did look like it was built well.

I have one on "hold" until mid-September (he can't sell it to anyone else). It will be mine for $650.00. I know it's a bit high, but it will be mine and it can't go away This looks to be a sweet rifle from all the reviews I have watched. It beats the S&W Sport I and matches (and exceeds) the S&W Sport II. The Colt has proprietary (not mil-spec) parts and no dust cover or forward assist). The Ruger is tighter than the S&W and is just as good as the entry-level Colt.

I'll buy my M1 Carbine later.

My buddy got a piston driven version. I looked at it. My opinion is that it is built out of rack grade parts. The only thing they did was design a piston. Horribly at that. It is made up of too many parts. It is nothing like a Sig or LWRCI piston, not even as nice as an Adams Arms unit. Like you, my buddy got his cheap.
Ruger is a name synonymous with cheap investment casting, low grade weapons. NOT operator grade weapons. Bill Ruger is rolling in his grave to know that his designs were in the end back burnered to the AR15 and 1911 designs that are at least keeping the company afloat.
The AR is a great design. Even hobby grade versions are worth $500!