I just bought for every day we were there. But the parks were predicted to be crowded every day and I just wanted it taken care of.
But I think it depends on how you like your trip. Like say you know some days you want to spend more time eating, watching shows etc and may only hit a couple rides then I probably wouldn’t. But if you want to hit a bunch of rides every day and it’s going to be busy then I would.
Also they just added space, frozen and I think Mickey and minnies run away railroad to the regular genie +. You no longer have to pay extra for them. That happened while we were there.