>And if you really just want to play games at a friends place or something you might as well bring a monitor then, if you are already considering a 20"+ laptop.

It's a pain to go back and forth from a friend's place and lug around a tower, monitor, and keyboard every single time. It's so much easier to be able to carry around a laptop. My friends and I used to throw LAN parties all the time and it was so much easier to just bring a laptop compared to lugging around a desktop setup.

Seriously, I'm a bit shocked there isn't more demand for mobile setups. Gaming is supposed to be a social experience, it's so much more fun to game in-person with friends. Having a high quality gaming laptop makes that experience so much easier.