Okay... so I took the R6 out today (parking lot exercises) and... wow, it is a complete different beast from the 250. She wants to lean, lean and lean. I wasn't scared, I wasn't nervous... the bike pretty much knows what to do. She is smooth and very easy to ride. I can't speak for the other 600 cc's but the R6 has totally stolen my heart. Vale will always be #1 ... but I can have an appetizer here or there.
The biggest difference for sure is the height... but you get used to it after awhile. :0) The real test will be when I take her on my first street ride which will probably be in a couple of weeks.