Even without the Replay feature the C chips are a welcome change and have increased my love of DNA mods. Been using a DNA250C for a few days now and Replay is impressive and a game changer for those who never really understood TC IMO. For those who have there DNA's dialed in for TC Replay won't be a revelation but a welcome addition for those coils that can give you trouble. I have been able to get much better results using Replay with a SS430 Clapton that I had just about given up on as my go to SS430 profile which works great with my usual SS430 wire. I was also able to get a premade SS316 coil from eleaf to work much better using Replay. I could have gone back and made a profile to work with these coils in normal TC but why bother when you have Replay.
Was never a big fan of the original DNA75, sold them all but one a while ago. The DNA75C is another animal though, got 1 for review and wound up buying 3 more. The 85% efficiency is a bummer but aside from that it is great as long as it is a dual battery version, my single 18650 feels like it is charging more than being used. Replay will be an awesome addition but until that day comes I will just use my normal TC builds for excellent results.