I use two 30" cinema displays daily. Bought used from two different eBay sellers. They are warm. I can feel the heat coming off them when seated at a normal viewing angle. They probably pull a lot of electricity but I really don't care about that as I do design work at my family's machine shop and our monthly electric bill is like $3500 no matter what.
Their color is maybe not the best, but improves as they warm up (with improvements leveling off after about 30 minutes of warm up). I start my computer before I intend to use it anyways.
I use an image calibration tool from Spyder and I can't get them to have exactly the same color, which frustrated me a lot until I separated them. I now have a standing desk and a sitting desk, 1 30" monitor apiece. Two 30" monitors next to each other is a lot of head turning anyhow.
There's no good reason to get rid of them that I can see, but they are not as bright or sharp as my 2013 Retina MacBook Pro. I love the 1x pixel scaling for my work, and the pixel density is a plus because I can run old school apps that don't respond well to HiDPI scaling, like old versions of Solidworks and Keyshot.
One of them has some slight image retention. I'm using it now. My solution is to set a screensaver to turn on after 10 minutes.
I think the vintage Cinema Displays are great, but they are expensive to ship carefully, so they may not be the most cost effective unless you can find a seller locally. I kept the boxes and peanuts mine arrived in so that I can pass them on more easily when I'm ready, but to be honest I will probably recycle these monitors when they break instead of resell them anytime soon.