I recently (finally) played a GB Pro on location - This location actually has 2 games, so I played both to see differences, playing 16 total games.
Took a few balls to get a feel for the shots. I had complete blast! The shots are satisfying, the music and call outs are awesome, and the games that I played are not nearly as unfairly brutal as previously reported. Sure, you definitely try to avoid the upper sling / outline area all together, but I felt the shots were definitely makable, and yes when you miss you need to recover quickly. In fact I was able to nudge save a few times off the metal ball guides. Difficult, but not impossible. The only tough shot for me was the right ramp, but I did hit it a few times, and its satisfying once you get it up to where the gate stops it. With the Scolari drops, try to aim for the outside edge of the drop for a safer shot.
Everyone has an opinion, but "boring" is not a fair way to describe this game. Storage Facility multiball is super fun. I was 8 ghosts away from Mass Hysteria (100 needed) - You can definitely get into a grove with this game. I had 4 games in a row over 100m and maxed out at 312m. Felt like I had a lot more to do for sure.
This game is going to be a runaway hit, and is totally worth the wait. I can't wait to play it again!