I am 43 and have been going to a Gold's (Rosslyn and now Georgetown) for years. I only lift too. The average age skews younger but it also depends at what time you go. I did not see any gymbro issues. Occasionally there are people hogging machines, but that can be solved by opening your mouth. I had more issues with female than male gym goers when it comes to sharing machines, but still it is pretty rare. People are generally pretty respectful. I only went to Van Ness ones but did not notice it to be much different than the other Golds in terms of environment.