Thanks for the welcome to the forum, there's a couple of points that I'd like to pick up on - Totally agree with the view of our congestion charge, the traffics just as bad and now you pay for the privilege of sitting in the gridlock. I work in central London so make the journey (by car) every day.
Don't get to the Ace much - its in the wrong direction! but we will be there for the Brighton run (if we wake up on time) if not, we'll be in Brighton sometime during the day.
With regards to the next bike, I think a 600 would be about right, but it depends on the top end - what MPH do you get out of one - at the moment my wife can reach the ton on the 252 - (admittedly with a following wind) but it will cruise at 90 without much effort. I know its true as I had to belt past her to let her know we were leaving the M25 at the next junction - and that made me go up into instant ban territory.
Is there anything I need to be particularly aware of on the ZL's ?
Oh and I guess the signature will have to change, just put the XS650 on ebay as we need the space in the garage (for a new ZL????)