Swat 3 was good, but Arma 3 is much more complex. You have a much wider range of firearms and projectiles with a much more open and varied environment. The swat games were almost exclusively focused around CQB. there was no modeling of breathing, strain, Gravity, etc.
all that being said, I would have liked to have mentioned it as one of the few games that actually tried to model firearms in a somewhat authentic manner.