Extra iron distance only has one advantage as far as I'm concerned and that's with the 3 iron... 220 or 225 as opposed to 215 is a big difference so you don't have to jump up to your 3W and then backoff on power guessing where 225 is. ;-)
I would disagree. Although I don't use apparel myself that gives extra iron distance (i.e. the C&M, Foxwind, and TG shirts), I can see a couple advantages.
If you are able to reach further with a higher-lofted club (eg. 9 iron), you can stop your ball better from further away. This could be particularly useful when hitting to an elevated green (eg. some of the greens on Bethpage and Olympic and Wolf Creek).
You might also get enough extra distance from your 3 iron that you could consider dropping your 3W from your bag and substituting a 4th wedge.
Those are just a couple possibilities.