This really depends on you.
For my family, park hoppers have never been optional. We consider it to be a necessary part of the expense because that’s how we like to vacation at Disney. If cost was a factor, they would rather wait longer to save up or honestly I think my teenagers would offer to pay for the hoppers themselves because they think it’s important.
I am very regimented and plan a lot in daily life, but for us a Disney trip is about spontaneity and enjoying the moment. I purposely do as little planning as possible to allow for this. We usually loosely plan one small part of each day (like morning EMH at MK on Tuesday or dinner at Ohana on Wednesday), but leave the rest of the day open to do whatever we are in the mood for.
The trip length is irrelevant for our decision. All of our early years the trips were 10-12 nights (10 park days). People always say PHs are “not necessary” for a longer trip, but I always found the value better when you divided the price out by 10 days rather than 3 or 4.
People also often say “no hopping with young children”, but we felt the opposite. When ours were babies/toddlers, we knew we were leaving for a nap anyway so the hoppers gave us the flexibility to go somewhere else that evening and didn’t really add any extra travel time.
Now that everyone is older, the hoppers give us the ability to split up and to ensure we get to do whatever we want. If the kids decide to sleep in one morning, my husband and I have the freedom to walk over to France and grab breakfast even though we are planning to go to Animal Kingdom later that day. Or if my son and I aren’t tired when everyone else is, we can hop over to a late EMH at MK.