@Emiliano Bolesani:
No problem, glad I could help!
Something to note is that every keyboard is different, between same models that are a generation apart, and even between two identical models purchased from a same store. Some brands like business laptops, and consumer lines that happen to mention keyboards in their front page (like Macbooks' butterfly or MSI's steelseries) make effort to control quality to certain extent, while others simply don't.
I personally look for 5 things in a keyboard: travel, actuation force, material quality, layout, and backlight quality, in that specific order of importance. Ideal travel is higher than 2.4 mm, but that's not happening in the consumer section anytime soon. :( So the next thing I look at is the actuation force required to press each key, ideally around 70 g for me. When its lower than that, keys lose tactility, essentially the ability to quickly go down and spring back up, and I easily notice since I'll lose ~10 wpm. Keycaps should be made of anti-microbial plastic (rough grainy texture) or hard metal. Some people are pretty stubborn on layouts hence won't buy laptops without their preferred design, but I've come to live with what I get, so long as the alphabet keys are normally sized and spaced.
I've had my hands on last gen's Spectres and I measured 1.6 mm of travel and 65 g of pressing force, both of which are rarity in the current ultrabook market. Keys feel metallic which is better than most laptops' smooth plastic, and the deck has little flex to it. As for the layout and backlight, they're decent enough. Samsung apparently falls behind in all five areas according to many reviews, which makes me wary, because the Spectre is only just good enough for my spoiled appetite.
To my knowledge, HP's Envy, Spectre, Probook and Elitebook lines have always made consistently good keyboards. And since I type a lot for a living and use laptops as my daily driver, a bad keyboard really isn't an option for somebody like me.
Some good reviews with commentary regarding keyboards:
Laptopmag
http://www.laptopmag.com/reviews/laptops/samsung-notebook-9-15-inch
http://www.laptopmag.com/reviews/laptops/hp-spectre-x360-15-inch
Daniel Rubino of Windows Central
http://www.windowscentral.com/samsung-notebook-9
http://www.windowscentral.com/hp-spectre-x360-15