I'm not sure re the poles. I carried them in 2008 and didn't really use them, so this year I decided to use them from the off. I used raidlights and taped them up, I'm not light, 80kilos, and found them fine. My main decision to use them was governed by the fact I had the Commonwealth 100K, 3 weeks later so I wanted to get through the UTMB with as least leg damage as I could.
On long gradual ascents I found them a god send. In normal fell races I often use hands on knees on the ascents, but with poles I could stand up straight.
I'm not doing it next year, 95% sure, but I said I wouldn't last year. Awesome event. Main advice would be start steady, get to Courmayeur feeling good and don't panic if you are slow early on, you'll make up loads later if you're feeling good.