Looking for advice on PF21 vs. PF25

Hi All, I have been using DDS:PF21 to run a simulation & alt history blog focusing on a USFL that never died. I am in 2017 right now and looking ahead to ending the sim after we finish the 2025 season. I am then going to embark on a "What if the WFL of 1974-1975 had survived" project.
My question is for anyone who had the 2021 edition of DDSPF and now has the 2025 version.
What are the primary improvements?
Would you recommend I buy either DDS:PF25 or perhaps 26 instead of using 21 again?
I have had no issues with 21, but if there are major upgrades or perhaps even greater capacity to customize (gameplay rules, number of weeks per season, etc.) I could see upgrading. Interested in any feedback about the various editions.
(And, if you want to check out my 30+ years of USFL simulation: https://apsbertsche.wixsite.com/mysite is the place to do it.
My question is for anyone who had the 2021 edition of DDSPF and now has the 2025 version.
What are the primary improvements?
Would you recommend I buy either DDS:PF25 or perhaps 26 instead of using 21 again?
I have had no issues with 21, but if there are major upgrades or perhaps even greater capacity to customize (gameplay rules, number of weeks per season, etc.) I could see upgrading. Interested in any feedback about the various editions.
(And, if you want to check out my 30+ years of USFL simulation: https://apsbertsche.wixsite.com/mysite is the place to do it.