Immediately upon its release, I sat down to check out the Director's Cut and see how it fared. Despite having played the original for over a hundred hours and then generally never wanting to return (I did write our walkthrough on the game, after all), I found myself getting back into the game like an old pair of shoes - familiar, and just as comfortable as ever. And while it's definitely true that this is indeed the "best" version of Human Revolution money can buy, the question of whether it's worth the $5 or $10 upgrade for players who already enjoyed the original game is a bit harder to answer.
Human Revolution was much-criticized for its boss fights, and rightly so. Contracted out to another studio to save on development time, a lack of communication between teams led to some battles which were stereotypical of big, dumb videogame boss fights. Aside from just being rather bland and poor in quality, what was most damning was that these fights effectively made all your choices in play-style and character building that Deus Ex is known for completely irrelevant, by forcing you to effectively shoot a big hulking super-soldier in the face about two hundred times.
Thankfully, this has been alleviated in the Director's Cut version of the game. Although the bosses are still something you can't avoid, now you are no longer forced to go toe-to-toe if you don't want to. Many of the boss battle arenas have been expanded in size and new options have been added for stealthy and savvy players who like to stick to the shadows. For example, take the early fight against Barret. In the original, you were effectively forced to grab an assault rifle and go to town on him while he yelled obnoxious insults at you; now, you can sneak around the much-expanded arena and hack security cameras and turrets to fight him indirectly.
This same holds true for the rest of the boss battles, which also have a fair share of options added. Overall, it's hard to complain about this change - while I would have preferred more options to bypass the fights entirely (like the killphrases from the original Deus Ex), I can understand why Eidos Montreal didn't overhaul them from the ground up. The changes made are still pretty substantial and the battles are no longer charring or disappointing, but something I actually genuinely enjoyed.
Beyond that, the changes are relatively minimal. The Missing Link, the game's DLC expansion episode, is now inserted into the main campaign rather than being a stand-alone story, meaning that now you experience it much more seamlessly, and your choices there carry over into the campaign's final hours. There's also the integration of the previously preorder-exclusive weapons and items into the game, without the "congrats for preordering!" message displaying every time you start a new game. Considering that the preorder items were not just pretty-looking goodies, but useful tools integral to the overall gameplay, it's great to see they are included as a standard feature now. New game plus mode is a nice bonus too, but I don't think people who have already enjoyed the game are going to want to go through it two or three more times.
The last significant tweak is the claimed graphical upgrade, but to be honest, this isn't very noticeable. The biggest and most obvious change is that the original game's gold filter has been toned down to allow for a wider variety of colors and a less monotonous look, but the other purported improvements, notably to lighting and special effects like fog and smoke, are borderline impossible to pick up on without doing side-by-side comparisons. Considering it's been two years since the original game released, I don't think it was too much to ask for a high-res texture pack, or improved dialogue animations (which are still as stiff as ever).
The Value Equation
The real question with Deux Ex: Human Revolution's Director's Cut isn't really whether it's worth getting, because at $20 USD, it's definitely the only version of the game a new buyer should consider. But, as it's been released as a paid enhancement rather than a free update for existing players (with variable discounts depending on if you have The Missing Link DLC or not), one has to wonder if it's really worth it.
Personally, I feel that $10 USD is a fair asking price if you played the original game but avoided getting any DLC. The Missing Link is a very good addition to the game, and the other small add-ons like the preorder items are also worthwhile if you have never played with them before. Where things break down a bit is if you already owned the game as well as all its DLC - even at $5, the changes are pretty modest unless you simply want to have the "complete" edition of the game, or are planning a replay or two.
With smaller developers like CD Projekt RED releasing free updates for their games with more additions overall, some people might even say it's unfair for Eidos to charge anything at all for the update. Regardless, it certainly would have been a good gesture for Eidos to have given players who owned both the base game and The Missing Link the update for free. Edios does deserve praise for bringing the boss battles up to par, but otherwise, the Director's Cut is a pretty meager improvement - if you've never enjoyed Human Revolution, you're in for a treat, but if you've visited Seattle and Hengsha before, you might want to look at other destinations instead.