I think it's very dependant on the person. So many people told me the Grado (and as such, Alessandro) line of headphones were the most uncomfortable out there. Some even went as far to say they sold their headphones for that reason alone - despite how good the sound was. But I can tell you, in my experience, they're not actually that uncomfortable at all. I could wear them for hours on end and not feel a thing - and besides, to improve the comfort you can just bend the head band back (which it's worth noting is something I didn't ever have to do).
Compared to say, a pair of HD 555s they're not going to be as comfy obviously. But infact, I find after a short period of time I always get achy ears with my set of HD 497s. What I'm trying to say is, IMHO, Grados are not that uncomfortable and it's very much an exagerated issue, but nonetheless your the most important judge at the end of the day. The only way you can really find out is by trying them...and if there is a problem, I'm sure it's nothing a pair of C-pads couldn't fix.