Is it totally insane to visit the Eiffel tower on a Saturday in May? If so we'd be there first thing in the morning, with reservations at 9:30 (the site still has tickets available for the day we're thinking of). I'm not quite so worried about lines (or should I be) but with zillions of people on the tower itself. I was there over 20 years ago on a weekend and it didn't seem so nuts. If it makes a difference the Saturday is May 24 (the day before Mother's Day in France).
Marcus if you have reserved tickets what does it matter? I have been visiting the tower since 1972, its busy when its busy..but you can still enjoy the view easily.
Get the ticket and go.. don't stress about things you will never be able to control. Theres more then enough room to enjoy the second level regardless of crowds. The top on other hand is such a small area .. and frankly so over rated view wise,, i have no idea why folks bother other then to say they "went to the top".
I recommend you get tickets and go... decide after being on second level if top is worth it to you . ( it is a seperate elevator ride to top)
Marcus on our last visit, the tower was busy. There were long lines at 4 locations. 1) base going up, 2) mid-tower going up, 3) top coming down and 4) mid-tower coming down. Still, we got the visit, views and great pictures that we wanted.