I’ve installed several now, the only negative I have found is with the use of cliffys. If you feel the need to use a cliffy with the protector then use a brand new razor blade and cut the protector so it does not sit on the cliffy. On some games for me cliffys impact the play for me, for example on my data east JP the scoop became a bit awkward but now with the protector it has given it a level feel and improved shot since there is no more lip due to cliffy. To me these are a no brainer upgrade, especially for routed games.