The problem I have with this is that it is not going to work for most people. Hear me out...
There's a comparison with UO's system, which allows anyone staying in a deluxe hotel to bypass the regular line. No pre-planning or reservation required, just show up, flash the card, and move right up to the head of the queue. If you're not staying at the deluxe hotel, it's VERY expensive to add this feature to your ticket. So, the vast majority of people at UO won't have it. I've used it, and cut my wait time on the "B List" rides by 30-60 minutes per ride. The Harry Potter rides didn't offer the "bypass the lines" feature when I was there, so I spent over an hour waiting in each of those lines.
G+ allows you to pay $15, so it's inexpensive, and allows you to make reservation after reservation but only for "B" list (C-D ticket) rides, and only one at a time. You might want to get out of the park by the early afternoon to avoid the sweltering Florida heat, but no... You make that POTC reservation at 7am for 5 minutes after 9am rope drop, show up at rope drop, rush to POTC, get on and ride it. Your next target ride is HM, Splash, or BTMR. You check G+... HM is offering a pass for 10:15, Splash is offered at 11:45, BTMR is offered at 1. Exiting HM at 10:40, you check G+ and it tells you that your next ride is at 3pm on either Splash or BTMR. You then check LL for 7DMT and get a 4pm time there, and it's $20 for that ride alone. You're stuck in the park waiting for your next ride 4 hours from now, so you have lunch, and get into a standby line for whatever you didn't pick as your next ride, waiting 50 minutes in standby, and then the next ride on your list, again on standby, waiting 70 minutes for that. You ride your scheduled ride, and then check G+, and find nothing left that day. Frustrated, the next day you decide to not buy G+. That day you wait 120 minutes for Splash and 90 minutes for BTMR because that day EVERYONE and their brother seems to have purchased G+.
G+ only works when few people buy it at a high price, or everyone buys it. If few buy it at a high price, it's UO's system that allows those who can afford it to not spend time waiting. If everyone buys it, it means that a regular admission ticket on an average day means you'll be spending the vast majority of the day standing in lines to get on a small number of rides, while those on G+ will have shorter waits in the fast line. I doubt Disney will publish how many people purchased G+ that day, or how many of them are in each park, although that could easily be done.
LL is the other wrinkle here. Disney has stated that top tier (A List, or "E Ticket") rides are pay per ride, or standby only. I can see people buying $30 FoP LL's to avoid the 2 hour standby line. Depending upon how many LL's are offered for the ride, this could cause a huge problem. We see it today with Fastpass. If you have a Fastpass, you might wait 30 minutes to get onto FoP when the standby line says 150 minutes. If Disney maximizes revenue by offering the vast majority of spots on FoP as LL's, the standby times will be "get in line at 9am and we might get you on the ride by the afternoon".
So, I don't see this scheme working for anyone but Disney, who has just found a new way to add at least $15-35 to every daily ticket.