No question these perform better for me than the AP1 versions I've used in the past. My number one reason to carry a 5 iron was to get a 6 club set for trade-in value. I now prefer the T400 7 iron (about the same loft) over a 25 degree hybrid. Scoring has other variables, but I'm more confident that in going for a green with an iron that I will hit the green than in the past. I can hit the 6 iron, but I'm not getting 10 yards more than the 7. Jury is out on a hybrid for that gap. Using Vokey 48/54/58 and 6-43 T400. I don't foresee updating irons with the next release.

I bought a set and have not been able to use them yet. I had commented on another T400 thread here and Don O had replied. His experience has been all positive. I'm in St. George Utah hoping to get in a few rounds once the weather co-operates and will give a review on my result.

I finally got on the course with the T400 today. I've not played since June of last year due to shoulder problems and still am not fully recovered from surgery to repair a torn biceps tendon, torn labrum, remove the bursa and general joint debridement in my left shoulder. My prior set is C16 with Nippon Modus 3 Tour 105 steel in R flex. The T400 with graphite definitely helped gain back distance lost without causing pain in the left shoulder. After warming up I was back to the distances I was getting prior to the shoulder problem. Very easy to launch high and hit straight. No problem getting them to stop on very firm, fast greens at Copper Rock Golf Club in Hurricane, UT.
I was skeptical, but have to say pleasantly surprised that the transition was so easy given the big difference in weight and flex. These deliver exactly as advertised. If you're losing distance don't overlook them. Today was salso my first chance to try my new TS1 drivers and was equally impressed. Kudos to Titleist for finding equipment to help out an aging, beat up old man.