The V11 is a great, great solo bike-maybe the most fun I've had on two wheels. As for passengers, they should be 4' 10"" tall, have a well padded posterior, and be slightly inebriated.
After a grueling 300 mile trip with my wife on the back of the Rosso Corsa (she had the addition of a gel pad and sheepskin cover) I solved the passenger comfort problem by getting a BMW R1150RT (and kept the Corsa, of course!). Mom can't believe the difference. Then again, we're in our 60's so comfort on a motorcycle has taken on a different meaning.
There have been some other threads on this site regarding two-up on a V11. The general tone of the responses seemed to be that they are not good two-up touring bikes.