I used to train on a military base, college gym, and my sparsely equipped garage solo. Now I train w/ a group of serious individuals out of a guy's garage. We have chains, bands, GHR, jerk boxes, bumper plates, and close to all of the relevant shit.
Plus, there is a guy pretty much my exact mirror in terms of bodyweight/height, so we get competitive. He can kill me in powerlifting, because he has 100lbs on squat, but conditioning, bench, deadlift, olympic stuff, we can compete and push each other. We haven't really got into it yet, but we are approaching it rapidly, so I expect many good sessions where we both have to step up, which will be a very powerful training atmosphere.
Additionally, being with a group of serious lifters, we tend to run into more serious guys and recruit them to train with us. We have a couple female lifters too, who show up and train without being intimidated.
Being part of a team or group is cool, as we all push ourselves to do more things. Good sessions will happen when you have a bunch of serious lifters in the gym, but getting outside of it is something different entirely; There is a strongman gym close to us, that we went to the other day to give it a shot. I probably would have never went by myself, but as a group I showed up and did relatively well. I got to lift some stones, deadlift a car, and pick up a frame with more weight than I would have thought possible. I got some good feedback from a pro-level guy, that makes me want to train harder to get better.
This is all awesome.