I'm still with the i15 irons I bought back (grrrrrr) after finding the Burners went South and they're way more forgiving, although in theory they shouldn't be.
I also went Rapture, G10, i15, Burner 2.0 and each was a big step up but for me, right now, the i15 are way better than the Burners. When the Burners were new they were in a different league.
Maybe I need to clean the grooves a bit.