I notice a difference in the way my gelding’s movement looks and how he feels under saddle too.
In steels, he is a decent mover (not getting a good piece of the hack at small A’s, but not embarrassed to still give a try) and he feels a bit heavier on his front end, especially at the canter-- not heavy in my hands, but heavier steps, if that makes sense.
In aluminum, he could get 1 or 2 in the hack without question. He is also much lighter and uphill at the canter.
That said, I do also notice some foot soreness at venues/rings with not ideal footing when he is in aluminum-- different time of the year, same venue with steels and he is happy as a clam, no soreness.
I agree that aluminum does trash their feet, so he only gets them during the “winter” season, Nov-April, for the bigger shows (WEF, HITS etc.), and then goes back to steels for the rest of the year for the smaller A’s.
Like others have suggested, if it were in my barn, he would have steels year round, until your more competitive show season starts.