Yes, the 20 became the 25, all the same parts, but with an externally adjustable seat retainer being the change. May will say the cost is not justified, but if I could get my hands on the kits, I'd likely do it (withing reasonable cost). I've got 4 MK-20's.
The bigger "upgrade" of the 25 is the composite piston as the others were quirky with mushy lock-up. Those are worthwhile, and to me, a no-brainer.
No Longer Awaiting my Kraken.....