This movie came out when I was a kid, I loved it.

The Reconstruction involved someone other than Sam Fuller taking his production notes, etc, and going through a ton of unused footage, and splicing together his idea of what Fuller intended.

Well, I have yet to see a Director's Cut that didn't have me singing the praises of EDITORS.  This was no exception.

The new footage added little, if anything. to the original strong story.  

SPOILER*********************************
One part, in particular, had Sarge and the horsemen confronted by a mob of "angy" Volks-geezers, apparently seeking to stop the Ami's advance into the Fatherland.

Sarge threatened to kill them if they didn't move, very tense(not), but they moved.    

Other scenes were mostly of the German nemesis in his travels from Africa to France, talking to civilians.  Fleshed him out a bit, but not adding much.  An pretty extended scene with a Nazi widow was just shoehorned in.
 
The "new" footage seemd, mostly, to be very choppily edited in, maybe they couldn't find the entirity of it, but I didn't think it played any better than the original, worse if you count the now choppy editing.

5.1 soundtrack was a bit tinny, lots of base for explosions, but the mid range seemd thin.

Image quality was very good.

Haven't watched the extra stuff yet. Ther is an entire extra disc.