I thought I'd post an update. I sold the Beretta CX4 and made a tidy profit. Now I'm deciding to keep or sell my Sig 516. I bought this carbine in 2012 and really haven't shot it much at all. I don't like the quad rail and the gun just feels heavy to me. Sig has stopped production of the 516, and I'm not optimistic that they'll support the platform. The piston system makes the rifle interesting to me, but that's the main draw. If I sell it, I'll likely roll the money into a DI carbine. If anyone thinks of a compelling reason not to sell the 516, please let me know. I'm ~80% decided on getting rid of it.