Just back from a week using G+ every day except arrival evening. I'm sold. I loved it! I had that old "skating above the crowds" feeling I used to get with a good touring plan and strategic FP+ usage. It was fun! This thread was invaluable in pre-planning our approach.
Knowing which ride to choose at 7am was the first key in setting up the day for success. For us we would decide together each night, based on reports from this thread and our must-do's, what to get first. We did Slinky in HS, Jungle Cruise in MK, Test Track in EP, and Safari in AK.
Knowing when we were eligible for booking the next G+ was the second key. If you forget you can look by faking like you are trying to book a new one and it will tell you won't be eligible until _____ time. Super helpful. We did double and triple stacks some days. I walk slow with a walker and do not back track and we made this work for me.
Knowing that as soon as you ride a ride you should book the next G+ reservation (even if you need to cancel and rebook later to get a better time) is the third key. Just know that if you are eligible to book because you just used a G+ you should do that before cancelling and rebooking something else or you will loose a stack. I made that mistake once and another person in our group did as well.
Knowing that, although you don't absolutely need G+ for shows, it can be helpful is the fourth key. Our first full park day was AK, and I didn't think we would need G+ for shows, so I didn't get one for Lion King. Waited 20 minutes. Didn't make it in to the 2:00 show, got a snack and waited another 30 minutes and did make it in to the 3:00. Show. That didn't feel like a successful use of Disney time. So, we learned our lesson and went ahead and got G+ reservations for Disney Junior and Beauty and the Beast in HS. We did Frozen early in the day without G+ because we were not eligible for our second G+ yet. As we approached shows the CM were telling people the next show was full at Frozen and Disney Junior. They let al the G+ people in first, so at Disney Junior our family was able to sit front and center and I got a bench seat. This also meant I wasn't standing as long. Happy benefit for me.
A BIG Thank you to everyone who has been posting and sharing experiences and strategy ideas here! You helped make our extended family trip wonderful for myself and 5 Disney first timers.