I think I'd ask experienced MaxPass/Disneyland posters what they think. Seems like Genie+ at WDW is almost exactly like MaxPass was at DL. We've been to DL twice where we got to use MaxPass, and liked it better than FP+ (not the paying for it part, but the 'not having to lay out our entire park day 60 days in advance' part). So I'm optimistic that Disney has worked through some of the kinks already with MaxPass - unless I'm naive and MaxPass and G+ are more different than I'm reading.
Makes me wonder, though, how the BG/LL situation will work. Will the people paying a premium for ROTR be in the same line as the 'free' BG folks? Or will the BG line become the pseudo 'standby' line, and IAS/LL will have the priority there like G+ will for other attractions? Many things to work out, that's for sure. And for all the negative posts out there blasting something that's not even in use yet, there are also many positive posts willing to accept the change and see how it can even improve on the experience. I'm in the latter group, waiting to see how it works out. But I do reserve the right to be negative later, if necessary!!