I have a 280AI and I really like it. I would do another in a second.
I agree with JE, if you are shooting the heavies I think there is value in the AI. The extra capacity helps as I think the 280 is marginal for velocity at 168gr plus bullet weights. Based on my experience, loading to the same relative levels of "hotness", I don't believe the AI competes with the 7Mag. YMMV
All of that being said, if I was set up with dies, loads, drops, etc for the 280, and it was doing everything I needed it to, I wouldn't go AI. If your current 280 is not doing everything you want it to, you may want to research if going AI really will get you there. You may find that to get a major/meaningful change in performance you would be better served going to a bigger 7.
FEENIX is absolutely right that there are reams of data on this subject, and it is worth researching to see what you find. My personal experience (just mine) is that all other things being the same, an extra 150fps from an AI vs a standard 280 is not even close to reality. Remember, I am an AI owner, and a very pleased one at that - I don't think you will be bummed with one, just make sure your expectations are in line before you make the change.
Good luck
Brandon