No, but I've heard it's supposed to be a great place. Going with a couple of mates from running club and have taken a couple of extra days either side to allow a bit of sightseeing. Course looks reasonably flat so hopefully I can knock a few minutes off my London time (assuming a decent build up).
McF - nice report. Well dug in, like you I found it incredible how many people were stopping and in need of assistance. Was good to run with you for a couple of miles, although I think it was miles 9-11 rather than shortly after halfway? I reckon you've got a 3:15 in you with a bit more luck with injuries.