I can tell you first hand that the older 90's stuff is exactly what the doctor ordered when hitting big wet/dry and high friction surfaces.
I use an old Piranha/C pearl and a Danger Zone when bowing at some local houses near my home. They hit better than urethane and don't over-react like most modern stuff. ALL new equipment, even the Tropicals which are the lowest diff ball on the market, hook too much off the dry when on nasty wet / dry lanes.
I will concur with this assessment! I bowl in a high friction house, primarily. The oil conditioning has changed, and the pins have changed, but the lanes are the same. So, based on this, I see my balls moving at a different breakpoint than when I used to bowl in the nineties. Other than that, the friction is still the same.
Therefore, my benchmark ball is a blue Hawk. Followed by a Demo-Zone for a little heavier mediums. And I keep an old pink, 3D Offset on stand-by in the car. Last season, I shot a 299 on a particularly quirky shot with the 3D.
So yes! The nineties balls do come in handy. Rule of thumb: "The first one who finds it, gets the gold." As in getting lined up! I find these 90's balls particularly useful if I want to avoid another player's line on the lanes. And even if I am in the track area.....they don't just jump off the spot like the newer stuff!