I think it can be a good deal.
We have WDW passes that we bought for 10 days and have the non expiring offer and the hopper. I think it averages out to about $50/day.
A single day single park at DL is $72, and a single day hopper is $97. So for us, it makes perfect sense.
My understanding is that if you have a hopper option on the WDW ticket, you get a DL hopper. If the WDW ticket wasn't a hopper, then you don't get the hopper option at DL.