Is the K74UR 5.45x39 Upper from Olympic Arms any good

Hi, I was wondering if any of y’all had experience with Olympic Arms K74UR upper: http://www.olyarms.com/shop/upper-receivers/k74ur.html

I want to build an AR chambered in 5.45x39 and it seems like my only option but I can’t find any reviews of it. I just want to make sure I’m not wasting my money