We (family of 5) have never had park hoppers before, but got them for our upcoming trip (10 day tickets). We got the Canadian discount though, before the ticket price increases. At the current ticket price, I don't know if we could have justified the splurge. We got them for this trip for a number of reasons:
1. This is our first time going in the summer. We figure we'll do more afternoon breaks, so if we're leaving and returning anyway, we want the flexibility of going to a different park in the evening.
2. DS and DH are big Star Wars fans, and if they love RoTR, I'm sure they'll want to try to do it more than once. But two full days in DHS would be too much for us.
3. Our kids are older, and can stay up later (without massive meltdowns the next day), so we'll be able to experience more of the nighttime entertainment than we have in the past.
4. We're going during Halloween party season. The kids will want to see MK fireworks, but we may not want to spend all day at MK on the busier non-party days.
5. Since we're going in August, we decided we'd like to try out the water parks. Upgrading to PH+ was just a few dollars more per ticket than one visit to a water park would have been.
Also, this will very likely be our last big family trip to WDW (at least while our kids are "kids"). We won't have that mentality of "if we don't get to it, we'll just do it next time". Hoppers will give us a much better chance of doing everything we all want. It feels worth it - hope I'm right.