I'm playing through the WiiU version right now and own and finished the PS3 version with no DLC, so here are my two cents, but keep in mind that some differences may come from playing on different pieces of hardware:
When it comes to presentation and eye candy, the differences are minimal, but I prefer the old version: the Director cut doesn't have the yellow tint that covered everything, which improves the game's color palette, and thee graphics are more sharp: problem is, this added sharpness forces the games engine to show its age as its rough edges and limitations have become much more visible.
EDIT: forgot to mention something: the annoying textures pop-up effect (where the game is covered in very low res textures -or no texture at all- during a few seconds while the high-res textures are loading) is completely gone.
When it comes to the game's interface, the Director's cut wins easily, but it may be linked to the fact that I own the WiiU version, which actually uses competently the gamepad.
The DLCs are perfectly integrated in the overarching stories: the added missions have been turned into main quests which you're bound to make: if anything, it makes the original vanilla version looks like it had been deliberately kept incomplete.
The boss fights themselves are not that improved: it's the arenas where you fight them which have been expanded and allow for more creative strategy, but they may have made them too easy: Remember Barrett, who was virtually impossible to beat if you had a stealth build? I Finished him with the puny 10mm pistol, and didn't even get a single wound during the fight.
The mooks' AIs are still ridiculously stupid, though, and the loading times remain long enough to be annoying.
I'd say the director cut is more enjoyable, and I don't regret spending 20 bucks to get the game, but then again, I never bought the DLCs, so your mileage may vary compared to mine.
