We have always, every single trip, purchased hoppers and used them, and enjoyed them. That said, the new ticket structures and prices are making us revisit this strategy going forward.
My husband has already decided that the next time he comes along, he would rather only go to one park a day and spend the ticket savings on club level and/or good dining and dinner shows. My daughter loves Disney Springs and could easily spend a couple of mornings or evenings there instead of park hopping. I love visiting and dining at all the deluxe resorts and could happily make several mornings and/or evenings out of that. And after just spending over $500 for a six-day hopper for my mom in December (and that was before the price increase!), we are seriously considering going hopper-free in December 2019.
We are all adults, and don’t even visit the pools, except for the pool bars! If you are adding pool time, that further reduces the need to spend time in the parks.
As other have said, you can always add the hopper option once you are there, if you decide that you really miss it.
However, if you have already planned enough fun non-park activities, there is a good chance that you won’t. The GF is gorgeous, with great access to the Poly and CR for dining and outings. Enjoy!!!
Edited to add: Just read that you are required to get the hoppers, so decision made. Free dining for a large group is a great perk, so you are probably getting good value there.
Have a wonderful trip!!