During my last trip into New York City, I made a special detour to the Herald Square JCPenney with the sole goal of checking out the MNG by Mango collection, which just launched in August at select JCPenney stores (read: not in my state) and jcp.com. My understanding is that this is genuine Mango clothing, shoes and accessories, not a watered-down diffusion line, and the quality and prices are consistent with this fact. I used to peruse the Mango boutique on Michigan Avenue when I lived in Chicago, so I'm familiar with the look and feel and the JCPenney collection is pretty much the same. Personally I think what you're paying for is the look, that chic, European, modern, urban vibe that you just won't find at the Gap. It's not that MNG by Mango is overpriced per se, but it isn't cheap: A structured black wool trench with an asymmetrical zipper really caught by eye but I gasped at the $249 pricetag. Not unreasonable, especially if you wait for a sale, but I can do better elsewhere.
Everything I tried on ran true to size (true to European misses sizing, that is, so it's a little on the small side) including the shoes, except for a slinky strapless cocktail dress - I had to go up two sizes just to zip that thing. I wanted to buy a couple things that were on clearance, including a plaid tunic ($27), embellished tee ($19) and nautical striped top ($9), but they were completely sold out of my size. Unfortunate. Overall, I liked what I saw and I'll continue to stalk this collection for deals on styles you won't find at Old Navy but can't afford from Shopbop.
More photos after the jump. Let me know if you have specific questions about any of the items and I'll try to answer in the comments.