I think most people will tell you that since ball technology switched from wound balls to solid core balls, very little performance is lost unless they are stored in a severe environment. Newer versions may have some minor performance advantages but older models deteriorate very slowly. If you wanted to go to newer ones, donate the old ones to your local High School golf team.

The old balatas would unwind after time, but you shouldn't run into that issue with modern balls. They should be fine.

The Pro V-1 was introduced about 18 years ago. I still have some original Pro V-1s and can tell you from my own experience there is little difference between their performance and the performance of the new ones. From what I've read the solid balls "cure' and get better with age, not unlike a fine wine. I'm a major golf ball finder and even now hit Pro vs from all the years they were made with little or no difference. Hit last years balls and some from this year. I defy you to tell the difference (except you may end up liking last years a little more).