My response is pretty much "eh". It seems the laziest solution, just stuffing the systems from both games in there at once in the hopes it will keeps fans of either from complaining. Neither system was perfect, having both doesn't solve the flaws of either, and having that many ways to fly around a map not hardly big enough to need it could easily feel goofy. It's too early to say for sure since a couple sentences doesn't tell us how they work, but just because you can't please everyone doesn't mean dumping every ingredient in the soup will give it the best taste overall.
But they didn't just toss them together. They gave the carriage an initial purpose, and then allowed you to choose.
I imagine most people will go to the towns in the carriage, and then just fast travel the whole game.
But the carriages will still be there so it doesn't "Break people's immersion"
To be honest I think it's the best possible solution to such a controversial problem I've ever seen,