If the price of 3D X is below 5K, I think I will get one. I take photos for my family, ISO 3200 is good enough for me. High MP will be great for the future when you play the photos on your TV. In 5-10 years, UHDTV will be ready, and you need 30MP(for 4K) to 122MP(for 8K) for your UHDTV.
How do you figure that? 4k resolution is 4096 x 2340 (unless you mean QuadHD, then it's 3840x2160) requiring at most 10 megapixels, and UHD 8k is 7680 × 4320 for about 33.2 megapixels. I regularly mix Canon DSLR stills with 4k RED footage, and have to downsize or crop the stills.