I have a PWS Mk 112. It's the only AR I've ever owned, but it functions flawlessly and is pretty accurate with match grade ammo. It's an absolute blast to shoot, and about the only thing I'd consider selling it for is the HK.
When I bought it, it showed up with a VERY significant defect that I couldn't believe would make it through any company's QA/QC dept; there wasn't any rifling in the barrel! It really soured me on the brand initially, but the retailer and PWS worked to get me a replacement upper in under 2 weeks, and I'm glad I kept it. That being said, the only reason I hadn't bought the MR223 was I wanted a short barrel. Now that the 11" is available...