CrossFit Geo is a great community. The instructors know their stuff and know every member and what they are capable of. You will improve your technique, strength and cardio and somehow manage to have fun while busting your arse. Plenty of regulars of all ages - right up to 50-somethings - giving it a serious go.
I wanted to give crossfit a go because it looked like fun. 3 years ago I underwent a back operation and I was concerned that I would not be able to do any of the lifting and that it was not for me. I found the instruction at GEO to be very good with attention to detail with focus on safety. I have found that I have gained muscle, confidence and have gotten more out of crossfit than I have gotten out of about 10 years of going to a normal gym.