Transports in HoI III actually were the sole reason i never enjoyed playing the USA or Japan in HoI III. I am glad that they got rid of them, not only because it reduces unnessesary tedious micromanagment, but also because it GREATLY helps out the AI, which now can do propper naval invasions.
I like the compromise that you can simply give a move order and they autmaticly ship themself to their friendly destination (can be intercepted!) and that naval invasions actually take quiet some time to plan out before you can execute them and that the complexity also affects the planning time. You might be able to plan the island hopping in a few days, but something like d-day would take several months of planning.