That is what I find to be best. I've been with the hyper-schedulers who have every minute planned. If something takes too long, they have to still do everything but they rush it. So, you might have the hour drive to the next destination, but as soon as you get there, you drive back since you need to get on schedule, rather than actually enjoy what that destination was. And you certainly can't skip that two-hour drive because then you somehow "miss" seeing it, even though you miss seeing it by leaving the instant you arrived.
But the opposite problem with no schedule is often worse. You spend 3 hours each day figuring out what you can do, and then by the time you get there the tickets are sold out. That is no way to vacation.
The rough schedule is ideal. Get some key things planned, like tickets to an important activity. Know what else you want to do, but go with the flow. When something is really fun, keep doing it and toss out another thing. You can always come back another trip.