I remember when I was in Paris with my class, in winter... It was SO bad, we weren't able to go to the top of the Eiffel Tower because it was still in renovation (even though it should be already finished when we were there >.>). When we went to the Versailles, we couldn't visit it, because the staff was striking! We saw only the gardens, and some Japanese people were making photos of us when we were waiting in the row in front of the palace o-o And when we were supposed to se the Pantheon, there were no electricity and it was also closed o____o
The next group, one week later, saw everything we hadn't. So annoying, but now I'm laughing at this ;p
Well, it's hard to see a lot during a short period of time. Personally I don't really like those organized trips, because everything is going so fast. You can't even take any photos, because in one moment in front of you there's a crowd of other people, and in the next - you're going fast to see the next thing ;___; but unfortunately very often it's the only way to visit those places, argh.
I also wish I would leave Europe and visit Australia, Asia, Africa. But, well, I don't think it's going to happen soon. If ever D:
But it's good you might have a chance ^^