I'm a Senior Computer Systems Engineer, Graphic Designer, and Video Producer. And I'm here to tell you that both the Xbox One and PS4 are both major letdowns to videogaming. As somebody at the top of the tech food chain and that's a gamer, I want you to know this:
Avoid the Xbox One. You'd think after the terrible Xbox 360 design, these guys would learn. Nope. Instead, they designed something large and ugly that looks like a 1993 shiny VCR, and wanted to play videogame-industry Nazi and lock it down with DRM and all kinds of idiotic security protocols. Microsoft only reneged those things because gamers were furious and they wanted to compete with Sony's PS4, not because they're generous. It's insulting and nothing says "screw you" like not buying. There's so many things wrong with the Xbox One, from its dumb name (did a child name it?), to its upscaled graphics, to its silly goal of being the all-in-one entertainment box in your living room. Microsoft can't even make a decent OS or videogame console anymore, but now they want to control all forms of media! It's sad, really. A once-respected tech leader, now a silicon circus. If you already own an Xbox 360 or PS3, you don't want an Xbox One or PS4 because all you're getting are ever-so-slightly improved textures, lighting, shadowing, and resolutions -- that you probably won't notice, anyway -- so save your $400 to $500 dollars and stick with your Xbox 360 or PS3 for the next few years...and buy a lot of great games. However, if you don't own an Xbox 360 or PS3, then by all means buy a PS4.
Note: I own both an Xbox and Xbox 360, but I am not a blind fanboy. I always buy the better product. I told you this because I want the next Xbox and PS5 to blow me away and make me say I gotta have it.