Scott,
One thing the 250 AI is, is efficient, and should prove to be effective also. I'll have to admit, when I was searching for a new Encore pistol round the 250 Ai never entered my mind. But it would lend itself to AI-ing very well, with as much taper as it has. I haven't figured it's effective range, but I know it's recoil would be least, of most comparable rounds.
I don't know why, it isn't more popular. I have only seen it mentioned once before also. But, if it does what you need it to do, and you like it. Then it really don't matter.
As with any cartridge, my biggest challenge comes from deciding on what bullet to use :wink: