Quoted from pete_d:TBH, I think it's a toss-up. Given that you're going to have to do something, and given that all the various options do address the basic issue, it's going to come down to what you personally would prefer.
If it were me, I'd start with Stern and get them to send the v3 protector. If I recall correctly, they are sending those out to owners free. Not sure what if anything they're doing about installation for owners who don't want to/can't do the work themselves, but if they're willing to send your local distributor or a tech out to do the install, even better. Let them take care of it. But even if you have to do the install yourself, you're no worse off than if you'd gotten an aftermarket option, and it's what the latest revision of the game design has.
Some people love to modify their games, to personalize it or whatever. Other people don't. Which kind of person are you? That will have a lot to do with which option you choose.
Even if you don't plan to install the v3 protector, get Stern to send it to you anyway. Then if/when you resell the game, it's right there with the spare parts for the game in case the new owner prefers that.
Between the two aftermarket fixes, I also think it's a toss-up. The metal version has the advantage of looking more "stock". It's just a beefier version of the regular metal protectors, if I understand correctly. But that does mean that theoretically it could start to deform like the actual original stock part did, just taking a lot longer to succumb. I gather than the seller of the metal version has a great track record in the community and is known for standing behind their products.
On the other hand, the NinjaCamp option gives you the opportunity to pick your color, and there are several different color options that seem to go really nicely with the game playfield art. They don't look stock, but they do look really nice. In theory, the material they make the protectors out of (3D-printed thermoplastic polyurethane) should last for a long time, maybe forever, and should never itself damage the playfield. But only time will tell if these parts actually hold up as advertised. That said, I have the impression that the sellers will respond right away if you have any trouble at all with them, so it's a pretty risk-free way to go in that respect.
As far as whether to keep playing the game for now, I think you should be fine, but keep an eye on the current metal around the scoops. If you see it starting to deform at all, give the game a rest. You've got plenty of other games to play there anyway .