I changed from 712 AP2's to 718 AP2 (PW to 8) & 718 AP3 (7 to 5).
The new AP2 was a feel thing. They are soft, with small-ish heads and are a thing of beauty and engineering excellence.
The AP3 was because I felt the 712 6 to 4 irons "plateau'ed " ie went more or less the same distance.

The AP3 long irons don't feel like the AP2 (they are not quite as soft) but boy do they go! I get a buzz from using them.
I have 716 T-MB 3 & 4 irons which have less feel than the AP3's but also go for miles.

So I would say that for me, the long irons have been changed based on technology and the short irons on feel.
Not sure that helps your quest... Best advice is probably to try out what you can get your hands on before you spend!
JT

Play with what works I say.

My 5-pw aren't titleist because I like what I have in those, everything else is titleist cause that's what works.

I’ve had a 712 mb/cb set for years and love them. I would suggest if it ain’t broke don’t fix it. With technology consistently moving on it would be nice to consistently upgrade but if we’re all honest with ourselves an extra yard or two from an iron isn’t really that big a deal. The gain in yardage is simple it’s mainly down to the lofts being stronger in newer clubs. Feel to me is everything and hitting the ball accurate is paramount from iron play.
Hope this helps.