I ended up buying the Alessandro's MS-1i. I ordered and paid last Monday, they arrived today. I used Paypal, it cost me 76€. There was no importation charge, I don't know why. Grado's SR-60 cost 85€ here, Senn's HD555 cost 78€, so it was a great price, I think.
My first impressions:
They're bigger than I thought they would be. I like their vintage look. I think they would look better without the larger cups of the improved model. When they're no my head, I mean.
Comfort is fine, they make my hears a bit hot, I don't know how I'm going to use them in the summer. I mitght try the HD 414 or the bowl pads some day. The pressure can make my hears hurt a little after a few hours, but I think I just need to get used to it.
They have ZERO isolation. If I shut the music down, I can hear exactly as if I wasn't wearing them. They leak some sound.
The sound is very good. The bass is round and defined, I like it very much. All the sound feels very clear. You probably hear this from everyone that has just bought their first pair of decent headphones, but I hear things in the music that I didn't, or had not noticed.
I want to thank you all very much for all the input, you were very helpful. I think I made a great deal, and I satisfied my curiosity about Grado's.
I'll try not to come very often to the forum: as an amateur musician, I've already got enough things on my "will buy some day" list, I don't think I need to enter the audiophile world.
Cheers, happy Christmas everyone