Just finished the game. Coming from the perspective of a completionist (I think I did all the quests in the game except a couple "tasks" that were long and had practically useless rewards), I think this game's length was just right. I was ready for it to be over by the time I got to the point of no return. Though I'm not 100% sure what the required path is, you can miss at least 50% of the content (likely 75%) by only doing the main quests. I think my playthrough was somewhere around 30ish hours.
I think the game is most comparable to Deus Ex in terms of world and level design. There are almost always multiple approaches to a problem - lethal vs. nonlethal, kick the door in vs. crawl through the ductwork, dialogue your way in vs. hacking or lockpicking, etc.
The best parts of the game are the character progression/leveling/skills, dialogue options, "dungeon" level design, and consistency of the other characters reacting to your choices and the state of the world as effected by you. I lost count of the number of times I found something before I was "supposed" to, reached the point where I needed it, and was able to say something like, "Oh, you mean THIS thing?" and the NPC reacted in a believable way.
My biggest critiques are the loot and AI. Equipment upgrades are rote and by the numbers and frankly boring, and NPCs couldn't care less if they're being burgled so long as they don't see you doing it.
Overall, I'd give it an 8/10. The writing and follow-through/continuity of plot lines is phenomenal - definitely in the top tier of video games. It's solidly enjoyable if you like RPGs, dialogue, and world building, but forgettable if you're not interested in talking to NPCs, reading logs, and diving into relatively shallow lore.