It's not really worthwhile for my family. We've been to Disney parks 12 times in the last 10 years or so, and we've only bought park hoppers once for Disneyland and we only used it once. It didn't feel worth it in the end, we would have been better off staying in the original park (DCA), as the other (DL) was a mob scene and we didn't get on any actual rides. Everything was all screwed up because I think ABC was filming the Christmas parade and Mariah Carey had things all crazy by IASW.
Anyway, we usually pick a park 6 months in advance when we do the ADRs, regardless of what the extra magic hours end up being. If we don't want to have dinner in that park, we'll have dinner at a nearby resort. And we have a pattern, always go to MK on the first day, EPCOT on the second day, etc. Only do FPs and shows in the afternoon. Mornings are for rides, rides, rides. And we're commandos, naps are for other people. We get there at rope drop and leave when everyone is ready to cry at 9 or 10 pm.
If you like to drift around and aren't focused on a goal (15+ attractions in a day), hoppers might be for you.