Yes they are doing new baffles for existing users including sealed cans. From a mod 4 to the eco baffles are the numbers that I put up above. Going from the previous generation (mod 3) it should be even better.

It would definitely be like a brand new can. I'm pretty sure they will cut it and re baffle it vs just trying to do a brand new one with new engraving. I don't know if they can legally re engrave a new one with your number on it but who knows.

They have a bunch of new baffle designs that they let existing owners upgrade to. You have to look at their site and see if your can has an upgrade yet.

Definitely the 9mm was a great improvement. Not only do the baffles on the 9mm lock together a lot better than the old ones, it is definitely more quiet.

I described it like this before: can you tell a sound difference between the full length 9mm can and the K version? If so that's roughly the gain in performance from the old baffles to the new ones using the same can orientation.

In my opinion it's definitely worth it for 9mm.

I will probably do just the Mod 3 and shoot it side by side with the others and see if it's worth it to do the others.