Wow, that's actually very nice in terms of RAM usage. Right now in chrome, with only 6 tabs open I am using (according to about:memory)800MB of RAM[1]. I may very well switch back to Firefox if I can get performance like that.
Also, yes, I do often keep read at this width. Web pages usually do not span the entirety of it, so the eye movement is kept to a minimum. However, I spend most of my day in a view closer to [1]this one. You'll notice that the monitor is just large enough that 2 standard width web pages fit on it perfectly.
Not sure what the discrepancy is there.