Completely boring golf club setup analysis follows:
I acquired a set of used 710 AP2s last summer from a buddy of mine who hangs around with a lot of low-level pros and is somewhat of a club ho. They were fitted with KBS Tour Stiff shafts, standard loft and lie setup. I hit them very consistently, nothing spectacular about the yardage, but loved the feel. The ball flight is a little high, but manageable.
Late last fall my 8-iron lost a battle with a tree in an ill-fated attempt to hit a flipped-over backhanded shot that was resting against the tree's trunk. I went to Dunns to get the shaft replaced, but they didn't stock it, so I was going to have to order the shaft, have it shipped, and pay for install. Total cost was going to be around $50. They had a good condition 710 AP2 8-iron in the used bucket with a TTDG S300 shaft in it for $25, so I bought that instead.
I immediately noticed that my 8i was now flying about the same distance as my 7i. Odd, but I worked around it.
Went to Dunns this weekend with a bud who was looking to try new clubs, and I hit the 712 AP2s (along with the CBs and a few other sticks). Tried the 712 AP2 with KBS Tour Stiff and with TTDG in a few heads. The TTDG was getting a slightly lower launch angle, slightly higher ball speed, and more distance every time.
I thought this was pretty interesting, how two stiff steel shafts with only subtle differences could produce such a consistent difference in distance. Particularly surprised that it was the TTDG that went further, given that it is a heavier, lower-launch shaft. I'm naturally a high ball hitter. The AP2 isn't exactly a high launch iron, but it does have some weight in the sole, more than what you'd find in a blade or more traditional forged CB. I'm guessing that the slightly higher launch properties of the head, with the slightly lower launch properties of the shaft, produce a more ideal launch angle and smash factor.
Now I'm thinking about replacing my irons. Stupid launch monitors....