Organising a Trip to Europe

We are fortunate enough to have the opportunity to travel to Europe in October. The question always arises as to what photography gear I will take. On a trip to Thailand last year I took the Canon G11 point and shoot. While it was great due to the compact size, there were quite a few occasions when I wished I had the 5D Mark II in hand. Dashing around on the beach at the Railay Beach resort at sunset comes to mind. Most observers would dismiss my actions as just a tourist (which I was) but would have they taken another look if I had the 5D with the killer (and heavy) Canon EF 70-200mm L f2.8 IS II poised for action.

In planning our trip to Europe I am going to compromise. Take the 5D but with only one lens and flash. So what lens to take? I currently use the wide Canon EF 17-40mm L for my real estate and landscape work, however 40mm really is quite restrictive from a touring point of view. Two possibilities come to mind:

The 24-70 is a favourite for weddings and is heavier and bulkier than the 24-105. With the slightly more compact feel, longer reach and image stabilization, I think the latter might be the choice as the walkaround on tour. What do you think?