We got back today, and were in Costa Maya this week. Our party split up. My DM and DS went to Tropicante and had a great time. My DM is exceedingly cautious and was a little nervous about it before the day, but said her experience was wonderful. Both DM and DS had a great day at Tropicante, and were very glad they went. She never felt unsafe, and said her only moment of nervousness at all was walking out of the really touristy port area to find the cabs, and that proved to be no problem, either.
DH and I went to Chacchoban booked through DCL. We considered booking directly with a local company with a good reputation, but we considered with the rather short amount of time we were going to be in port, and didn't want to risk running late and missing the boat. We did the family version of the excursion because DS waffled about whether he was going to do the ruins with us or the beach with my mom. We absolutely loved our tour guide, Luis, and thought he was one of the best guides we'd ever had on any tour, ever. (That is saying something - we've been on a lot of tours over the years.) Not sure if you can request a guide if you book through DCL, but we were very, very impressed.
The other ruins "near" Costa Maya are simply not doable when the ship is just in port for 5 hours. On those relatively brief days, Chacchoban is really your only option for ruins.