Burgess values transformation a decent amount, and has famously said that a book without a hint of "moral progress" or personal transformation has no point and is better left unwritten. Thus, despite all the crime Alex commits, at the end of the day, he grows up. The transformation Alex experiences in the novel is hard-earned and long overdue; it is also freely chosen and deeply personal for him.
Alex's "transformation" in the last chapter is completely superficial and will not last, for he has come by it due to boredom with his current life and out of envy for Pete's "normal" life.
The transformation F. Alexander has experienced might more appropriately be called degeneration. He goes from being an aspiring writer who loves his wife to a vengeful political dissident.