Taking it on it's own terms, it's still not very good. I admit I have trouble separating it from the original series, because, well, it's a reboot. But there are some damn annoying glitches in that game that I experienced. Not to mention the mechanics are very annoying.
My list of problems.
1. Annoying glitches: There was one section of town, where the audio was replicated over and over on itself. Take a random conversation between 2 guards, and have them start the conversation over, while the original conversation was taking place. Also, have another cluster of guards, having the same conversation, within earshot of your hiding spot. So you end up in this insane echo chamber of guard chatter, while you are slowly moving through this area, which means you hear it a LOT.
2. Also, I ran into a spinning guard glitch, where one of the patrolling guards got stuck in place, and starting rotating in place at blurring speeds. This made him impossible to sneak by, because it directly effected his cone of observation.
3. Not getting the lighting/stealth system right This one is terrible. You will be standing in an obvious bit of lighting, but you are hidden. Or, contrarily, you are clearly hidden in the blackest void of blacky blackness, and yet your visibility gem is bright as day. It makes it unreliable to where you can actually move safely. And in a game that is built on light/shadow for it's primary game mechanic, this is a deal breaker.
4. Not being able to jump when I damn well want to was annoying as hell. You could only mantle over specific things, which severely limits your methods of exploring and traversing the map.
5. Not being able to stick rope arrows wherever I damn well want to was also annoying. The game limits your rope arrows to very specific points, basically railroading you down specific paths, with no options on how you wish to proceed. Do you want to try and string several rope arrows across a ceiling, and leap from one to the other? Sorry, not going to happen. You can stick it in that one spot, and that's it.
Honestly, I would suggest you play Dishonored instead. It's got a better story, and better mechanics, and the Thief reboot was desperately trying to capture the lightning that was Dishonored, and failed miserably. At being a Dishonored clone, and at being a Thief reboot.
Don't get it.