The two attractions I see mentioned most often are POC and Haunted Mansion which were largely walk ons before FP+ and now usually have 30 to 45 minute waits on moderate and slow crowd days. ...My 60 day window opened for FP+ last night and I used it for the first time. It was easier than I anticipated, actually a little fun, and I wasn't blocked from anything (except Frozen M&G which I didn't want anyway, and that was 30 minutes after the window opened). Just keeping my fingers crossed that our Magic Bands work without issue.