TL:DR Whatever the original got right, this game got wrong. whatever this game got right, the original got wrong.
Deus ex HR is a game loved by many and even said to be better than the original. I disagree. this game is a few step above mediocre.
Pros:
AI and boss fights are greatly improved
The game is difficult
Hacking is entertaining
Cities feel alot more alive
Cons:
Alot of the game mechanics have been downgraded (no area based damage, no skills, no melee weapons, Items take up more storage in the original but granted you can upgrade that)
Realism was thrown out of the window (this is what made the original special to me. Its not some stupid unrealistic bs)
No console commands
not really a negative, but this game annoys me by how many references it makes to the first game. I don't mind it but they put too much references.