1. That will be a busy time period this year. If you are only planning say, 4 days in the parks, you might want G+. If , on the other hand you'll have more like 10 park days, then you can afford to take a slower pace, IMO.
2. Unfortunately, you will also have to pay peak G+ prices.
We have done both G+ and non-G+ days at WDW. The choice is a very personal one that depends on a number of variables in how you plan to tour.
Favoring G+: high energy touring, hate waiting, want to see everything, want to maximize your time, don't mind using
MDE in the parks.
Less inclined to buy G+: on a budget, relaxed touring, don't care about riding everything, don't care about coasters/thrill rides, happy to meander-touring, low crowds, dislike using your smartphone (or don't have one), days with a visit to Disney Springs.
When the parks are crowded, we tend to buy G+. IMO, HS is miserable no matter which you choose. You might pay $24+ for G+, but miss out on getting Slinky. On the other hand, if you don't buy G+, expect to wait 70+ minutes for Slinky- even at Rope drop, and then to wait 120+ for all the other popular rides. If you buy G+, all the worthwhile HS passes will be gone by 1pm: MMRR, MF:SR, Slinky, TSM, and ToT. (also RnRC, but it is closed for a rehab.)
There's also Rise. It is an expensive ILL. No matter what, the actual attraction takes about 18minutes. Rushing to it at rope drop = you can't be in line for other HS rides until you are done riding it. At RD, a LARGE group of people rush to Rise. Odds are slim that you will be at the front of that crowd. Most of the day, the standby will be a LONG wait. We have been on Rise a number of times, and find our HS days are often better if we skip it, especially during busy weeks. Many people choose otherwise.
In AK, on the other hand, if you arrive for rope drop, and don't plan to hop, then there is less value in buying G+. Again though it depends on your tolerance for waits, and how much you value going on all the attractions and seeing all the shows. If you plan to skip one or two of the popular attractions and/or rope drop, and/or stay past 3pm, it is easier to do without G+.
If you are eating multiple TS meals, you will have less time for rides. for some folks, that = not getting G+. Other folks might see added value in having G+.
If we visit WDW over busy weeks, we tend to buy G+, and not just G+ but the multipark G+. The only ILL we have ever bought is FoP. I don't think any ride is worth $25 per person. Yes, we've been on all the WDW rides. On busy weeks, our approach is to skip Rise and only go on 7dMt late at night or skip it. We tend to leave HS mid-day. On short trips, we skip HS.
On busy weeks, we tend to make good use of peripheral park hours. We arrive early +stay out late, but often take an afternoon break when crowds peak. To make good use of G+, we book passes for our evening park, but that requires keeping track of all the times. you not only have to keep track of all your passes, but also when to book each pass. Some days, we don't feel like making that much effort.
We also tend to skip G+ on arrival and departure days, especially our departure days.