Quoted from mrgregb123:
I decided to play some games on my new DI with the factory 'cliffy' in the SIM hole. I played about 300 games on my original DI with no protector at all so I feel I have a good reference point.
I found that the shot from the upper right flipper is exactly the same. Their cliffy does not prevent any shots from going in that would have otherwise gone in with no protector at all.
The main difference seems to be slow roll-ins. While fast roll-ins (eg. off Bing Bang and left ticket standups) went in just as often as no protector, slower roll-ins tended to deviate at the lip of the way-too-thick factory protector. If I had to estimate, you'll lose 1 out of 5 SIM card shots with the factory protector vs. no protector.
I got nervous from people on here saying the shot was impossible to make with the factory protector on, and this is not true at all. But there is a small advantage in having no protector or presumably the thinner Cliffy protector.
On the other hand, the phone scoop seems to hold up pretty well with just the mylar around it. Makes sense based on how the damage to this hole actually occurs (using my older DI with 300+ long-length plays as a reference). I do not believe a metal protector is needed here.
Its definitely also needed on the phone.