Its good all around work out for muscle strength, muscle endurance and aerobic exercise. People criticize it for not being the best work out for any of those things, but for a lot of people, that combination is the best compromise for a goal of moderate strength, cardio fitness and calorie burning for the amount of time spent.
yes this sums it up well. and as i said above its fun to compete against each other and race, good way to meet people, etc. gym rat setting you are usually in your own world, gets lonely sometimes