Better beans, actually, given that it triggers on 4-mana spells as well
There are no new cards in Lorwyn Eclipsed that put +1/+1 counters on anything, but there is a rule that kicks in if a permanent has both +1/+1 and -1/-1 counters on it
Craterhoof Behemoth When youre playing green and you want a clean way to end the game, this is one of the first cards people think of
5/4 Green is generally the best at hating on artifacts and enchantments, but the possibility of reliable, repeatable, and protected removal
This also unlocks Open the Armory as a tutor option
As for creatures which have better power/toughness, let me recommend Commander Eesha, Emeria Angel, Guardian Seraph, and Shalai, Voice of Plenty over Aven Trooper