I totally agree that riding in a group like that will totally make you stronger. When I stopped going, my average speed plummeted. I was pretty strong there for a while. I ride mostly with my relatively new husband now and we just don't push each other the same way.
As for someone hanging back with you if you fall off, don't worry about. IME, the guys love to be chivalrous and there's always somebody looking for a valid excuse to take it easy, especially this time of year when people are starting to burn out. So don't feel guilty if someone rides in with you.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher