Same ending, some scenes are trimmed, some different shots of Zombies getting shot in the head, stuff like that.

Uh...as far as I know, the Euro versio is included in that set, no?

It is indeed included in the Ultimate edition boxed set.:)

I actually liked Argento's Euro cut quite a bit. Most of the music is Goblin, and you get to hear several cuts not featured in the other releases. The Goblin music, rock-oriented, seems to make a number of the scenes scarier for me personally.

You may also notice that alternate dialogue tracks are used--quite often you'll be hearing the sound recorded during production, whereas the American theatrical version and the longer "director's cut" feature a lot more dialogue that was rerecorded in the studio. I actually prefer a lot of the dialogue as it was recorded during production, and you can hear this in Argento's cut. For the most part the actors' deliveries are subtler. (Example: "Wooley's" dialogue before the SWAT team charges into the apartment building.)

I had never seen it before getting the DOTD ultimate edition, and after I watched it, I was really glad that they included it. Nice to have it.