I can see where your coming from, riding a MotoGuzzi, must be one of the most memerable rides I've ever had (you don't want to get the throttle wrong in the corner
).
weights in about the same as a small tank, and being kind, lets say it's sedate handling, spares are strictly reserved for the well off, and build is patchy at best (don't kid yourself your buying anything like a bmw quality machine).dealers are few and far between, and they don't carry a fast shock( expect delays on not service items).
the Griso at least looks cool, but at under 90 hp for a 230kg bike it's not going to set the world alite. steer angle is also a bit relaxed, and wheelbase a tad longer than most.
The Breva, well don't even look at the 750, about 40 hp or something like that, sorry but a moden piece of tat. The 1100, well not great, but better thatn the 750 (not hard that)
Generally not a bike for those who love to ride, not winter proof either, more a design statement, if you like then fine, just don't expect go & handling like comtemperies, lot of money too (OK cheaper that BMW's) I think the big 1100s go for around the £7.5-£8.5k mark.
to me these fit into the group I would consider only once I'd given up riding.
always said when I do I'll get a harley or beemer
Hope that helps put you off 
Cheers Mark