The other night before I sold my old Karsten 1 irons i took them to work to hit them alongside my gamer Pings on the GC2. I only did the 8 iron...
Ball speed. 109. 116
Launch. 21.3. 19.4
Side spin. -284 -112
Spin. 8155. 7184
Carry. 143. 159
Distance. 144. 161
I used a pro-v 1 for both. I think the lofts are only 2 degrees apart. The old Karsten 8 iron, like previous Pings is probably a half inch shorter.
The old Pings felt just as good as the new ones.