Having bought the AVL three weeks ago in India, and having read a heck of a lot about this debate before and after, on both the Indian site as well as this one, I'd say, welcome to the club! This is the start of the RE ride, this agonizing over the decision.
My 2 cents:
1. I think both are REs. Or, if you prefer, neither is - REs stopped being made in the UK in 1968, to take an extreme view.
2. The AVL engine is rightly reputed to require less maintenance, although it is not maintenance free - we would not want that to be the case either, would we?! A review of it as a buy for corporate types allowed that it will keep you in the board room and not in the garage, by the way.
3. I think that the AVL engine has a higher power/torgue/speed potential, in line with your needs- provided you run it in really well. That running in comment applies to the iron engine as well.
4. I don't think that in looks there is really that much difference between the two engines.
5. The only place where the AVL engine loses, is in its sound. I know that the stock sound gets better with age and with silencer mods, but it never quite approaches the mellow thunder of the iron engine in full - or even half! - song. You have to hear the two to know exactly what I mean. Its like the difference between a fine aged wine, and one that is rough around the edges. I was out on my AVL 500 yesterday morning, and parked on top of a hill to cool the bike off, when I heard the note of an iron engined RE coming up the hill and it went by me. It was a fairly new bike, but the sound was exactly what REs in India, and in the US too, I imagine, are known for.
Hope the above helps you decide. As some here have said, the best thing to do is to have both in the stable!
Have fun with your decision. Once I have learnt the skills of maintaning the RE, I will probably swap mine for the iron engined version. If nothing else, for the joys of running in one again!