I'm just back from the Best of Eastern France tour and I thought I would share some information about our time in Chamonix. I know for many people, Chamonix is the highlight of the tour (It's what made the tour sound so appealing to me and my husband) and I get the impression that nervous anticipation of the weather is a concern for the tours. My experience ended up being a little different from what I expected, so I thought I would describe my own impressions.
First of all, I thought we would have one full day in Chamonix to explore and if the weather did not cooperate on that day, we would not be able to fully enjoy the town. The weather reports were not encouraging as the trip progressed: some days rain was predicted on that full day (a Monday) and other times it showed partly to mostly cloudy with a chance of rain.
We actually arrived on Sunday around noon, so we had a full afternoon and all day on Monday to enjoy the town. This was a big bonus! Our guide, Chris (Fantastic, by the way!) led us on a walk through the town ending close to the gondola. We went up to the gondola and found out that rides required a reservation and that the next available slot was at 2:20 pm, so we bought our tickets and got our reservation. I got the impression that the reservation system was new because I don't think our guide mentioned it to us and she seemed surprised by it. (People who went the next morning had a similar experience, arriving at the gondola at 8 am but not able to ride up until after 10 am - that was the soonest available.)
So tip number 1: if you want to go up the Aguille du Midi, get your reservation ASAP! I don't think you can get them online/in advance, so make a beeline for the station to get them.
We went up both gondolas to the top of the Aguille du MIdi but by then the gondola over to Italy was closed for the day, so we could not do that. That might have been disappointing but since we never expected to be able to go up on the first day at all, it was such a bonus that it didn't matter. We decided we would try again the next day, but the gondolas up to the top were all crowded (packed) and I was starting to wonder if maybe we should forgo the gondola to Italy possibility and instead go on one of the other gondolas in the valley.
Also, we had heard one person on the tour ask our tour leader about paragliding (you see lots of people paragliding from both sides of the valley) and so we decided "when are we going to ever get this chance? Let's do it!" Chris jumped through some hoops to get us a reservation but in the end she got one for us the next day at 12:30 in the afternoon. It was from the other side of the valley.
So the next morning we decided to skip the Aguille du Midi (we didn't think we would have time to make it to Italy and back again) so we walked over to the other gondola on the other side of the valley (10 min walk) called Brevent and we thought "well, it's only 9 am now and we could take the ride up and get back fairly quickly". We noted that this gondola seemed to be moving quickly: much smaller gondola, with benches so you could actually sit and enjoy the ride.
Tip 2: If you aren't sure about going to Italy, then don't even go up the Aguille du Midi gondola. The Brevent gondola is so much more pleasant: less crowded, more enjoyable, no "packed like sardines" feeling - and I think the views from that side of the valley are actually better! You can actually see Mont Blanc across the valley. Spectacular!
We then rode down and had lunch and made it back to the gondola in time to meet the paragliding company; and we did it. Myself, my 70 year old husband, and our 75+ year old friend (who has some mobility issues due to back issues) all were able to do the paragliding. Fantastic experience. All in all 6 of the people on our tour managed to go paragliding, and our tour leader told us she never saw that many people doing it!