This post is a little late but I would like to add my opinions on the upper playfield vs the pro.
I own a premium LE and played a pro several times. First either one is a great game, so lets look at the differences. The elevator multiball to start with is easier to get on premium. On the pro you need to shoot the ramps before qualifying lock. On the premium you only have to shoot an orbit or the drop the target to get in the elevator, there is an adjustment for the difficulty but I haven't messed with it. Once in the elevator your ball goes up to the upper playfield, on the pro the elevator scoop is always open and the ball goes in and shoots back out and if you lock a ball it does so electronically like the coffin on Metallica pro. The upper playfield then has 5 standup targets you try to hit all to qualify double scoring, there doesn't seem to be this function on the pro. Then back to premium, you either shoot the elevator and it drops down into the lock for toy box or you shoot the upper orbit to start double scoring. If you miss, the ball falls down the right ramp. About the right ramp, on both games its a narrow shot so it needs to be accurate. The premium is a steeper ramp and a little tougher than the pro which has a long gradual slope. The ball is not stopped on the upper playfield, it simply obits around and back to the right flipper just like the ramp of the pro
So overall, IMO the upper playfield of premium is integrated into the game perfectly. Maybe it doesnt do alot but It doesn't take anything away from the main playfeild and adds just the right amount of game play and strategy without breaking up the flow of the game. But the pro gives you a great game as well. Either game is fun to play, they are just different mostly involving the elevator & double scoring. I would consider it an extra toy.