I just didn't like how DX:HR, you still needed to invest in combat skills to beat some of the bosses. If you went heavily in stealth, you were SOL on some boss battles.
That was changed in the Director's Cut I believe. You no longer have to fight them, I believe you can stealth around them now.
I'm going to look crazy, but I have never played a Deus Ex... I even own them in Steam.
But, wow, I'm going to start one here very soon.
Just to add something that is rather consistent in both DX1, DX2, and DXHR is "heavy" weapons aren't really needed or even the most effective.
The pistol and melee (or takedowns) are the most effective weapons on all 3 games with grenades as support. Especially if you factor in inventory management and ammo supply.
Although in DX2 you could do some funny cheese with the spybot aug and/or rocket launcher.