As previously described, I decided to finally buy for home an HP z24n, exactly the same model I use at work. At work I'm using two such screens and I deal very well with them.
At home I get the same kind of symptoms that I had with my BenQ. The only differences between the office and home are
1) The lighting / room brightness (I assume, the major factor);
2) I'm using Ubuntu at home while Windows at the office (I don't believe this to be a factor for me);
3) I'm using HDMI at home while I'm using something else more recent in the office. Plus, the hardware is different. I don't really believe I'm susceptible to that kind of issues as some of you guys are, so I don't believe this is the issue.
I'll have to start my journey of trying to replicate the kind of lighting I have in the office. I think the main issue is that the screen at home looks a lot brighter than in the office because the lamps I'm using are not that strong.
I'll let you posted on more details in a couple of days.