Phil,
Congratulations!
I have noticed a gain of 7-10 yards per club from my AP3's (coming from 2010 TM irons). The shaft contributed as much as the club head itself. Ill never go back! ahha

I've only hit them on simulator. My normal 7 iron goes 155-160 yards, I was hitting the AP3 around 175-180 yards. So it looks like 20 extra yards for me, a little over a full club in extra distance. I'm hoping Santa brings me a new set for Christmas. :)

Josh

I'm over a half club longer, but the consistency and launch are the primary benefit. In part due to a heavier shaft that smoothed out my tempo.

A lot of that will depend on what you currently play. I hit the AP3 and was close to a club longer than my AP2

I switched from the ap2 710 px flighted to the ap3 px lz. This was the first for me being fitted to a set of irons and found that I was getting too much spin and the ball flight was too high with the ap2. Once I got it within the suggested range I gained 13 - 15 yards. Thanks to the Titleist fitter.

I have the same experience as Nate. About a club longer coming from AP2s. Of course now the air is colder and a bit heavy, I may a bit longer in the Spring and Summer.

I myself graduated from a set of cast SS cavity backs with offset, to a set of 718 AP2's and my new clubs are 15 yds longer. Same swing.

Review the 718 Iron Specifications on this site. If you use 3 yards carry for each degree of loft difference between clubs, then that will explain most of your distance gains. Loft of a club is the primary determinant of distance. Next is length of the shaft and next is weight of shaft. The effect of shaft length and shaft weight is secondary to loft and varies much more by individual. The 8 iron you purchase today was probably a 7 iron five years ago. Not saying it is good or bad, just pointing out some facts.

Thanks everyone!

The flatter loft may not necessarily explain the extra distance, you could be getting more distance due to the shaft. I got fitted a few month ago and went with C16's, which I hit much farther than the AP2 and AP3. I put this down to stronger lofts but my fitter said I was getting a higher lift angle and more height, so it wasn't the loft. I did try around 8 shafts and the best shaft on the AP2 and the C16 went the farthest, so I think the shaft has a lot more to do with the extra carry than the loft, IMHO.

I haven't had the opportunity to take the clubs out on the course, much to my frustration.
However at the fitting I was getting over 15 yards extra distance.
I used to play 12 year old Hogan Apex Edge irons. The new AP3 lofts are exactly one club stronger through the whole set. So the extra distance must be largely due to the stronger lofts, with a bit of technology and better shafts contributing to distance to a lesser extent.

Lighter shafts plus 3 degrees stronger on average that the AP2's equals you should hit them one club longer. Physics and math, no magic.