At the moment, I don't rate Aguero much higher than Rossi and I think that anyone who thinks Rossi is average has no clue about football, but I want the argie much more, even because they're a bit different.
At least I see in Aguero a player able to be a "one-man attack" in the future, like Tevez for example. Plus, in the future, I see Aguero among the better players of the world (top10 at the very least), Rossi not. And plus, I think Rossi would need better players around him than Aguero would, to perform at his best.