I voted other, because the Rock Polish set I would suggest is different to that normal set.
Item: Leftovers, Shuka Berry OR Peteya Berry
Substitute/Aqua Tail
Rock Polish
Earthquake
Head Smash
Aggron will only be getting in on things which don't like it. Most of these things, cannot scratch Aggron, things like Flygon locked onto Outrage, or CBTar's persuits cannot even break the sub, giving Aggron the ability to set up without fear of status, and counter some of his normal counters. In addittion, this set can be used in tandem with a Peteya Berry (Spelling XP), to increase Aggron's Attack stat as well as the speed boost granted by Rock Polish. Nothing shrugs off a +1 Head Smash, even Steel-type walls. Leftovers gives Aggron some bulk to come in and do it all over again, more often, and +0 Head Smashes STILL hurt. The amount of sweeps I get because of Aggron getting in on CBTar or an Outrageing Dragon, and setting up, and killing them, while the sub remains up, is astounding.
And, we're forgetting Shuka Berry allowing Aggron to beat some of his counters, by reducing Earthquake to half it's power, which will actually allow Aggron to live it more often than not. Although, we we use this methord, we should not use Subsitiute, and instead use Aqua Tail/something like that. Heatrna uses it sometimes, so why not Aggron?
That said, this set works because of the amount of free switch-ins my Latias gives it. I doubt that a self-supporting Aggron set would work as well without something to hit flying steels for Neutral Damage.