It is hard to say. It depends on if you are strictly a league bowler or if you bowl a lot of scratch tournaments. A lot of houses are still have high friction lane surfaces and/or lower volume house patterns. On those type of conditions, your older reactive covers will do just fine. If you are bowling on today's sport patterns or certain houses with a slicker house shot, you absolutely would need a stronger cover than PK 18.

Not much has really changed.  House shots can be played multiple ways depending on your style.

I agree with Avabob! They have not reinvented the wheel! Whenever I break out some of my older PK18 equipment, I am only able to use it for a game or so! It is still plenty strong for whatever you want to use it on, so have at it!