There are scoundrels like Han Solo, swashbuckling smugglers who never grow up, never settle down, never trade in the buccaneer life for the weightier responsibilities of adulthood. These are the guys who wear the same jacket and boots at seventy-five as they did at twenty-five, heedless of how silly they might look. Then there are scoundrels like Lando Calrissian, a bit smoother, a bit more ambitious, who translate their piracy into the broader realm of politics and bureaucracy, to whom the administration of a gas-mining facility is a step up in the world, not a step down.
Lando was never as cool as Han (which tells you just how cool Han is, since the Billy Dee Williams cool factor is off the charts), but he at least gave respectability a shot, becoming the mature, considered merchant-manager we meet in Empire. Someone with obligations to others beyond a his hairy life partner and a freight score. A Bespin businessman, a bean-counter, a problem-solver, a job creator. I've been a carefree rebel and I've been the guy going blind with spreadsheets. The spreadsheets are harder.
Lando was trying to do the right thing when the Rebellion stuck its nose into his operation, threatening to undermine everything he'd accomplished on Cloud City. He didn't ask to get sucked into their imperial entanglements. He had his own problems. Sure, he initially sold Han and the gang down the river to advance his interests, but that deal kept getting worse all the time, to the point that Lando threw caution and sense and maturity and obligation to the wind and joined the revolution. It's important not to minimize that choice. Out of all the rebels, Lando probably sacrificed the most to the cause. Not a hand, or a few minutes in carbonite, but his entire life's work. Lando gave it all up to roll the dice with the ragtag rebellion. You have to respect a guy who can do that. Also one who can seduce a princess, take a punch, and swirl a cape around his shoulders with the best of them.