The bold is exactly my feeling, and unfortunately my experience on 7/11. It's also the reason I wrote to Disney with my feelings on the event and its cost.
We never saw 55 minutes on Space when we were there, but 7DMT was still a 45-50 minute wait at 10:45. We had a plan, and stuck to it for the most part, but Peter Pan, Pirates, BTMRR were all over 20 minute wait at the time we waiting/riding. Also, Space/7DMT took us about 30 minutes each (in spite of Space's posted 15 minute wait). As a result we got a total of 5 rides in during the party.
I know last week it was reportedly lighter crowds and lower waits, with many rides being walk-on. It might fluctuate depending on how "sold out" an event is? We enjoyed the event's theming, but it was not the "ride more wait less" event that they are advertising- at least not for our party.