I made the transition from 2x Dell 24" U2412M to a Samsung 40" HDTV (40MU6290). I already had a GTX1070, so didn't need to invest anything additional in that area.
I had used the 2x U2412M as they were reasonable priced IPS displays that could be calibrated for Lightroom/Photoshop work (photography being my other money sucking pastime). Zero gaming.
I decided it was time to move up to 4K, and I tried hard to implement the
LG 43UD79-B. 3 times in fact, from 2 different resellers over 3 months. Supposedly "factory calibrated" (it was anything but), it did require tweaking to bring back to reasonable gamma (2.2) and temp (6500k) but it suffered terribly from color consistency across the screen, especially with red. A white dialog box on the RHS of the screen was pink by the time it was dragged over to the LHS of the screen. It was $550 at Costco on the thanksgiving period, I would have been quite happy if it wasn't for the color consistency.
I also decided that for my preference, 43" was just a little too big for my setup ... and I never ever thought I would say a display was too big !!
I ended up picking up a Samsung 40MU6290 when it was on sale at Frys for $329, and it's been lower (<$300) since. A couple of trade offs compared to the LG ..
1) LG had displayport and HDMI, Sammy being a TV is HDMI only.
2) The Sammy is a glossy display (lots of screen reflections) and it's low IRE tracking is worse than the LG. However, low IRE aside, it calibrated "good enough" and I've hung some cheap blackout curtains behind me and that's helped a lot with the screen reflections. My basement is my workspace, so have the ability to be "creative".
Pros: lots of real estate for the $, better LR/Photoshop editing experience, lots of space for RDP/KVM sessions (monitoring remote miners !)
Cons: Glossy screen (personal), I'm still trying to find the best viewing height/angle, and I ended up going with a wall mount for flexibility