Ok, I owe you a feedback of my experience in an (italian) gym. I got a free one-week pass from my flatmate for a gym she is going to next to our appartment. I didn't try the group lessons.
(1) The staff really wants you to subscribe for the longest possible period (it goes up to 3 years for 500 euros). When the lady understood that I just wanted to use the free one week pass she threw the paper on the table!(2) It is crowded, overheated and I found it more disgusting as healthy (sorry!)
(3) Strange atmosphere in the sense that people are usually going there alone, everyone is observing, and no one is talking to anyone.
(4) You are going and coming out of the gym dressed up with make up and perfect brushing. Obviously meaning that you bring all your clothes (in + out + sport + swimming) and shoes (outside + gym + flip flops), hairdryer, make up, towels...
(5) The standing of your gym depends on your purchasing power that depends on your social position.