He developed more comprehensive chops, but gave up the adventurousness of his playing and composition of the Milestone period. But while his own work with Trane was great from the beginning, I think his Impulse albums were generally unremarkable.
I saw Roy Hargrove last summer, and I found that he had finally grown into a truly expressive artist (and had put aside most of his silly stage shtick). Plenty of trumpeters had major chops very early on, and then grew into them.