Spartan totally destroys IronMan. Big time.
The thing about someone like Spartan is that in his improved form he is basically at a level that can stand up to Mr. Majestic. As in, literally trade blows with him.
Then to that add the abilities garnered from void, and you have a situation where Spartan simply 'ports whatever armor Tony is wearing into some black hole, and then proceeds to punch the now naked Tony with a fist that can make Majestros bleed.
Simply put, while IronMan is a really serious combatant, he is just not in the same league as Spartan. Spartan could dismantle IronMan in a number of ways, ranging from simply ripping him apart with his hands to using Void's powers to split tony apart on a molecular level.
Spartan 3.0 10/10.