Here's a photo of the spacers for the Avengers Pro, the short one is the factory one I had on my machine when it arrived (mine was from the first batch sent to the U.S. from Stern)... with a freshly waxed playfield, the ball would travel too fast up the ramp and the low spacer on the plastic was causing the ball to stop/lose momentum, to the point that I was getting about 80% of clean shots to the ramp rejected. This was super frustrating.
I replaced the short spacers with the taller spacers, and the problem is solved, for the most part... while I still get occasional rejects, the ramp flows 80% of the time, a huge improvement.
For those with Avenger Pro Machines, replace those short spacers of the game will not be very much fun, the ramp rejects will piss you off and ruin the game!! Initially I went to Home Depot and bought some round rubber spacers until I got these.. you will need longer screws also.
With looking at Eggbert's LE, the ramp plastic is a little higher than the Pro's and the ramp that flips backwards has a plastic that is even higher than the first clear plastic.. which IMO is the reason the LE ramp flows better than the Pro ramp out of the box.
I sent this info to Gomez, and he advised that all of the new Avenger Pro machines will have the correct spacers on them to correct this problem.