Just got up a Seiki 39" from Walmart.com for $329. After some flashing and calibration, its a beast! Highly recommended for day to day/dev use. Gaming, too, but not in 4k. It can do 1080p 120hz.
Can you elaborate on the flashing/calibration? Is that to get better than 30Hz at native 4K resolutions?
For coding / web browsing, how good is the screen (i.e. can you notice lag for those use cases). I have heard mixed things about the Seki 39" but it looks like it could be a great development monitor
I use one for development and love it. There is lag and it is noticeable - it's most noticeable for moving the mouse cursor, and it is somewhat annoying because it makes any mouse operation feel slower and less precise. The lag doesn't really affect anything else I do.
Still worth it for the price IMO, the screen real estate makes a huge difference in my productivity.
Flashed it with SE50UY04, the 50 inch models, firmware. Just extracted the zip, put the install.img on a FAT32 formatted USB drive, and went into the secret menu (with the menu open press 0000) and updated the firmware.
After that I started with these calibration numbers:
Contrast: 42
Brightness: 66
Color: 34
Sharpness: 0
Color Temp: normal
Turned off Noise Correction.
--These settings can be changed in the secret menu - other settings options.
Red Gain: 141
Blue Gain: 126
Green Gain: 132
Red Offset: 532
Blue Offset: 510
Green Offset: 504
DCC: Off
Backlight: 75
And modified it to my liking. Actually had my Macbook Retina open next to it and sort of color matched. My numbers could vary greatly from these. My backlight is at like 50.
Overall, I'm really happy with it. Yes there is a mouse lag, but the 50" firmware makes it LESS noticeable. Also tbh, you sort of get used to it. In my case I try to minimize mouse usage anyway.
