Our experience with these has not been great, in terms of crowds and lines still being longer than one may think based on the PR of shorter ride times. We have seen 30 minute+ lines quite often at these. Long lines for characters and so on as well. Sure, they're shorter than a 2-hour wait during peak periods, but they're not "short" as you may be thinking.
Again, your mileage (and the mileage of others) may vary, but we did a few of these and won't do them any more. By comparison, for example, the late night hours offered for Deluxe Resort guests are far better in terms of short lines and the ability to really get quite a lot done compared to a "normal" evening (on those nights we routinely got 10-15 minute waits -- and walk-on in the final hour -- for the most popular rides, at MK in that case).
Yes, your entry price is your park ticket in effect.