It's the people in the middle....who don't go frequently (1x a year or less) and who knew how to ride a lot of rides and enjoy a lot of rides in a day....those are the people who don't like FP+ from what I read here anyway.
I'd say I fit this definition of in the middle... I don't go frequently (1x a year or less), I knew how to ride a lot under FP-, and I enjoy a lot of rides in a day.
However I happen to like FP+. It works well to accomplish those goals. To me it works better than FP- did. i.e. I can now get on more rides with less total time spent getting on the rides than I could under FP-.
On the overall planning issue, there are two sides to this...
1) Does 2 weeks at Disney World take more time to plan than say 2 weeks to Hawaii or 2 weeks to Europe? No. It takes far less time to plan. If I had to rank them, I'd say:
2 weeks in Europe
2 weeks in Hawaii
2 weeks in Disney World
There isn't all that much to plan. I mean... it's making dinner reservations. Big deal. I can pick dine-in restaurants I want to eat at and make a reservation.
Then there's the Fast Passes, which take an hour to do an entire trip.
That's pretty much it. Maybe you'll plan some things like BBB, P&P, or whatever other incidental activities you want to do.
Planning a trip to Europe... Oh my. The currency, the maps, the learning about stuff, the prices, the getting around, it would just be months of intense planning. Compare this to Disney where your food, your transportation, even getting from the airport is practically handed to you. You -- pick some rides, and you can change them any time you want to so you can't really even pick them wrong. That's it really.
2) Then there is Disney vs other theme parks for the day-park experience. Well, this isn't terribly relevant because I would never drop $200 on a dinner at Six Flags. I would at Disney World. I would not take a look over QS menus at Six Flags. I would not care about parades, evening entertainment, fireworks, seeing the opening show, or meeting a character at Six Flags. I would at Disney World. So they're not the same. SF you just go cuz all they have are roller coasters and rides. You ride them, woohoo. A day at Disney we plan so many other things to do than just the rides. So in that regard, of course it costs more time to plan
a day at Disney vs
a day at Six Flags. As the OP said tho, they are a day at the park vs a resort vacation. If I lived local to Disney, the other stuff like eating there would probly get old, and it would reduce closer to a Six Flags. But fortunately I don't so when we go it's a special occasion.