First (unfortunately), the logistics. We were supposed to be picked up at the hotel at 8 a.m, but a minibus only arrived at 8:45 - after the hotel reception made inquiries on our behalf. We joined the main tour bus about 20 minutes later at a random point on the main highway north. I assume they forgot to pick us up... The tour duration is listed as 8 hours, so we expected to be back at the hotel by about 4 p.m - but were dropped off at about 6:30 p.m. Luckily, we had no specific plans for the evening.
TAMAR project is wonderful, the project visitor center is similar to a small marine zoo. OK, but not a must-see. The village resort is quite beautiful, but expect many tourist shops. The public beach at the resort is small and not really inviting. None of our group bathed there.
Guarajuba beach, where we spent over 2 hours, is beautiful, but don't expect pristine white sand and clear water. The sand is a typical 'sand' color (i.e. light brown), and the water somewhat silty. For those interested in swimming, there was a strong rip current.
Our tour guide was very friendly, and although we were the only English speakers on the bus (others spoke Portuguese, mostly, or Spanish) devoted sufficient time to us. Overall, though, it appears that the tour is seen primarily as a day at the beach with a little souvenir hunting, not a didactic trip.