My family is a timeshare owner through RCI and has been for as long as I've been alive. Every trip we've taken to Disney we've stayed off site in a timeshare resort. Even though we could not use EMH we've been able to perfect the art of fitting everything in in one full park day. Fastpass was an important part to that and I don't like that we now have to wait until after on site guests to reserve fastpasses instead of it being first come first serve. I recently booked a trip for next year with 12 people and figured I could easily plan for all of us to effeciently ride the rides, see the shows, etc. just like I've always done but with the new fast pass I'm leaning more towards just going to Universal instead which makes me incredibly sad as i've grown up on disney and have always dreamed of working there and making it a happy place.
Don't let the FP+ scare you. I booked my FP a few days before arrival without issue. We wee there on a Sunday during the opening of Star Wars Weekend and I thought we'd be In trouble based on what I read here.
We had no issue.