Not really a recommendation, but just read what you are getting.
We used Provence Panorama for a tour of Pont du Gard/Uzes/Nimes back in 2012. Now - I think perhaps we just had some bad luck, so I won't hold that against them. It's a 5 hour tour. The driver was new-ish to that tour - I think the regular driver was ill - and was about 15 min late. We had about 45 min to see Pont du Gard. At Uzes, the traffic was so bad, he had a hard time finding a spot to drop us off, and when he finally did - shopkeepers were on his case about it. Again - we had about 45 min - which gave us enough time to walk around a few blocks and pop into a church. Next was Nimes - where we were supposed to have entrance to the arena - except...because we were there Oct 2 or 3, the schedule had changed from Sept opening/closing times and we ended up getting there about 10 min after the arena had the final entry. Sigh. (He had gone to the Maison Carree first). So there was no checking at all about possible changes in closing times. The group ended up sitting in a park nearby for a half hour before heading back to Avignon. At least I had some ice cream.
Now - that's not to say that their other tours aren't good (they have good reviews) - and like I said, the stars were aligned against us that day I think. But def look at the number of stops and the length of the tour. If you can contact the company you use and see how long a stop there is in each place - 45-60 min doesn't net you much time at all, especially if there are traffic delays. I'd focus on a longer tour (8 hrs) with maybe 3 stops or so. You can always check a site like rome2rio and see how long the drive is between each place on the tour, so that would give you an idea of how much time is going to be spent in transit...in our 5 hr tour, about 90 min of that was driving, leaving only 3.5 hrs to see the sites.
We revisited the area in 2015 and had a car rental, so we were able to return to Nimes and see the arena and more of the city, and spent a little more time at Pont du Gard. With our own vehicle, we saw Nimes and Arles one day, spent a morning and early afternoon visiting Les Baux and Glanum, and spent a day in Aix (cut short by torrential rain, thunder and lightning, and some flooding - fun fun!).