According to my wait time apps I use in both DLR and WDW, Midway Mania has the following waits right now at 3:00PM Pacific and 6:00PM Eastern:
Midway Mania DCA - 25 Minutes
Midway Mania DHS - 40 Minutes
I'm highly suspicious of that 40 minutes at DHS though if they've gone to FP+ only. Maybe there was a breakdown or something?
25 minutes is a typical wait time on a non-busy day for Midway Mania at DCA, which has never offered Fastpass. At the same time today in DCA, Radiator Springs Racers is posted at 60 minutes, Grizzly River Run is posted at 35 minutes (it's sunny and hot today!), and Soarin' Over California is posted at 20 minutes. Tower of Terror is 15 minutes, and everything else in DCA is 5 or 10 minutes. The Little Mermaid: Ariel's Undersea Adventure is a complete walk-on.
But then we're comparing two theme parks that have taken very different strategies for expansion in the 13 years DCA has been open and the 25 years DHS has been open. To the point where today you have two established theme parks that have this to offer paying customers on a slower October weekday:
DCA open 8:00 AM to 8:00PM - 31 Attractions, 21 of which are Rides, 1 Parade, 1 Water Spectacular
DHS open 9:00AM to 9:00PM - 14 Attractions, 5 of which are Rides, 1 Water Spectacular
And with that said, I am
BAFFLED that TDO chose to do a "test" on making one of only 5 rides in this incredible shrinking theme park FP+ only. They couldn't try this out in Magic Kingdom instead, where there's more rides available to soften the blow? It's almost like this is a test to see how much they can get away with before their paying customers revolt.