We were in MK from 1-11:30 pm. We did Philharmagic, BOG lunch (had FP & preordered), ETWB, Stitch, COP, Buzz, face painting, Space, played Pirates Adventure, Aladdin, PoC, Splash twice, BTMRR, Monsters, and Space again. The longest line we stood in was the 2nd Space My. Posted 40 min at 11:00, but actually 18 minutes. Pirates was posted 30 minutes but only took us 6!
So it isn't the lines for us. Either coming at rope drop or staying late and using FP+ from 11am-7:00 on works great. I'm still thinking fp+ works for us. But a level 9.5 day with filming and FP+ kiosk lines: no way.
I think having BOG FP+ lunch, ADR dinner, and 3 pre-ordered FP+ in afternoon would make things ok for many in high crowd days. Those insane lines also disappear to walk-ons in the evening.
Glad to hear that MK works out for you. I think MK is do-able, with proper planning. For first-timers and those that want to do it leisurely/ on the go, it could be a very different (negative) experience.