One is grand action schlock. And... It knows it's schlock and that's not a bad thing.
The other is simply one of the greatest and tightest action films of all time. Ironically what gives Die Hard the edge is that it's about a truly relatable everyman, while Arnold is just a classic, perhaps THE classic example in Commando of the one liner spouting, unstoppable killing machine tough guys of the 80's. I mean... Is McBain really all that different from the film that is Commando? Where as in Die Hard when John is forced to jump from the rooftop in a desperate bid to survive he looks over the side of the tower and he doesn't give the audience some tough buy bravado... He says instead: "Dear God... Please don't let me die..."
And that's what makes Die Hard what it was, and indeed, what makes so many of it's sequels miss the mark on why McLane resonates with the audience.