I also have an old ZBook 15 and must say I'm also pretty happy with it. The weight is a massive pain, 3.3 Kg for mine, but on average I take it somewhere once

I also have an old ZBook 15 and must say I'm also pretty happy with it. The weight is a massive pain, 3.3 Kg for mine, but on average I take it somewhere once every couple of months at most so I can live with it. The big plus is that I haven't had to buy a new machine in close to 5 years and performance is on par with my Dell at work and certainly better that my crappy surface book 2 at my previous place.