I would suggest planning your days. Use the crowd calendars and check the schedules for closing times, etc. Which parks would you want to do on each day? If there are days that you want multiple parks, then get them.
We have never hopped before with kids, but we were always staying off property. The kids never want to leave, and they wouldn't let us take a nap no matter how much we all need it, so we usually just stay all day. If we need a break, we go into a sit-down restaurant, or ride the train around MK. If we have an early day, then we go to the pool, maybe head out to Downtown Disney later. My husband and I traveling alone always used hoppers, but in 10+ trips with the kids, we never once wished we had one. However, we did book hoppers for our next trip, staying at the Poly. Kids are older now and seemed more feasible to hop when home is just a monorail away. We shall see!