I just got a Lenovo Y50 with an i7 4x and a gtx 860m and a 4K screen. I hate it. At face value it should be a great laptop, but simply put, Intel integrated graphics can't really handle 4K. I've installed a 1TB Samsung 840 Evo ssd, and yet it's still not a fast experience. And then add to that the fact that windows is absolutely awful at display scaling, not to mention all the things that don't scale at all like java, and you end up with a user experience that's rather sub par.
Needless to say, I won't be getting another 4K laptop for a long time. 1080p is just fine. 2K works as well. But for 4K? Nope.
You're the first person I've heard really cry about their 4K display. Individual programs not scaling well is not Windows' fault. Most of this crap was not written to scale well to UHD resolutions, even Chrome took forever to adopt decent scaling (and text rendering). Then you state that the Intel graphics aren't good enough for 4K. Is the device equipped with an Nvidia 860M or not? Finally you stick in a 1TB last-gen budget SSD into a relatively costly device. A higher-end 500GB SSD would have been worlds better, or at least an 850 Evo. Your whole paragraph just comes off as suspicious.
i have a GTX 860m (the original name for the GTX 960m) and while its good for 1080p, the things going to choke to death at UHD...
Thankfully Ye Olde PC Games let you adjust resolution. If you cut it down to 1080p, it scales pixel-perfect up to 2160p. Boom problem solved. Then you still get 4K for web browsing and movie playback etc etc. It's not like like trying to run a game at 768p on a 1080p display, where the scaling is not quite perfect.