Well, where to start.
First of all, Disney's ticketing and reservation system is so overcomplicated. Our experience: bought tickets online, in advance, for a specific day with valid park reservation. Came to the gate and voilà: access denied. Incompetent staff at the gate, barely speaking English, talked and gestured 'more money' and refused to let us in. Headed to ticketing office and had to pay an upgrade to higher tier. Unbelievable, considering fact that I had valid park reservation.
Next one is Lightning Lane. An absolute piece of crap. First of all, it rarely provides sooner access than actual stand-by wait time. Then, it blocks you from making multiple chained reservations. And least but not last, it is so confusing in the terms of which rides allow multiple Lighning Lane reservations and which don't. Not speaking about fact that some rides cost extra money.
Summary: Disney is overpriced, confusing, badly managed and implemented in the terms of online ticketing and reservations.
Parks itself are nice, especially if you catch one of the less crowded days.
A huge disappointment is fact that some rides have the queues so terribly managed by a staff, that parties going for single riders (yes, it happens now and then) get on ride twice as fast than standard stand-by parties, even within the same ride despite being single riders.
Oh, and I have to mention our experience with Oga's Cantina. Staff placed us at the very end of the bar, to a spot where our party could not fit at all, rudely ignoring our complaints. When we tried to arrange in the space, the staff was also rudely complaining that we're blocking the path. Unbelievable and unacceptable.