reaganry I have a BenQ EW2440L. It is usable, but not perfect. It causes symptoms over time. Still better than most monitors, but not perfect. I also have a BenQ EW2740L. Still to my surprise, it's almost perfect. I'm currently watching TV on it and can do it for hours. I've been using it for months now. I bought another EW2740L to find out that it's not as good. It's more like my EW2440L. So BenQ uses different components. The model is sold out almost everywhere.
I can't really recommend it because it seems to be a lottery. The one that's perfect also looks like it has been opened (bent frame) and refurbished, while the worse one looks brand new. So I can't even say that it's BenQ's achievement that this particular device is great. Maybe the refurbishing process added a better backlight. The monitors certainly have a different color tone. I should note that I couldn't find any flicker on both devices with my oscilloscope.
But this monitor is the best I ever used and I hope it never dies.
Edit: There is one obvious difference between the two: The better one turns black (with backlight on) for some seconds when it gets no signal while the "bad" one turns blue. Everything else, including all settings and even panel and firmware information in the hidden service menu, looks the same.
Edit 2 (3 months later): The option responsible for black vs blue screen is regular menu - System - HDMI Auto Switch - ON/OFF. ON is black and OFF (default) is blue. So this is no hint for a better hardware revision but just a regular setting.