When his character is introduced, he has a chat with a bounty hunter that's come to collect him.
Solo is an underhanded opportunist that never plays fair when he can take advantage of his enemy. He blows the bounty hunter away from under the table in a surprise attack while they're having a conversation. He's smart.
His story line advances when he shows that under his intelligent, self serving behavior, is a conscience that occasionally results in him doing heroic, and utterly retarded things. Like showing up in the middle of a battle after he's gotten his payment.
Asshole then remasters the movies, releases them anew, and "softens" his character by making the bounty hunter shoot first. Now he's a moron.
It may be a minor detail, but Solo is the only good guy that doesn't have a dick up his ass.