Philgood80,
Firstly, I agree with the comments by LB, and in particular his comment about the current availability of suitable powders which now make the AI version viable.
I currently have 2 rifles chambered for the 25/06 AI (40), and the barrels in both were initially chambered for the standard 25/06 for the first 200 - 250 shots.
One rifle was a new Sako 25/06 Sporter (24 inch barrel), and the other was a custom made from a Sako L61R Action, Shilen 24 inch SS barrel, and Fajen stock.
I have had 18 years experience with the 25/06 AI case, and it has proven a terrific performer for me on medium game in Australia. Consequently I will always have one rifle chambered for this case.
Ballistically I have obtained a 200 -225 fps velocity increase with each of the 2 rifles when using bullets of 100 grains or more.
Typically I have found from both rifles, that you get 3,550+ fps with the 100 grain bullet, and 3,250+ fps with the 115 -120 grain bullets.
However, the standard 25/06 has proved to acceptable to thousands of shooters, my experience supports this, and would probably use this case if the majority of my shots were under 275 yards.
Although it definitely kills more emphatically at any distance, "dead is dead". So trying to be objective, I believe the main advantage of the AI version in the field is from about 275 yards onwards, where the extra velocity seems to give you greater margin for error, and hence more confidence in taking the shot. Hope this is of some assistance. Regards, Brian.