To follow on from what Mike said about the difference between a steel and Ti frame, I went from a Mk1 PA to a Mk1 MG and thought the MG felt nicer to ride, slightly more compliant and forgiving than the PA. However this may be entirely in my head because I'd paid 3 times more for the MG frame than I had for the PA.
It is absolutely awesome to have the Ti version of a classic design and it is my favourite bike, but I do think that if something did happen to it I would buy steel again rather than Ti (irrespective of price). Partly because steel is a bit easier to fix if something were to go drastically wrong with it, and also because I like to fly under the radar a bit and the blingyness of Ti makes you stand out a bit too much for my liking. The matt grey laquer of the MG is pretty good for keeping things low key and having taken off the decals you'd have to be a real bikegeek to know that it was Ti.