I joined 18 months ago, after going a long time as a lone wolf, and trying several squadrons.
It's great to be in a group based on personality (as in "all around good guys"), rather than on skill or "winning." I've been impressed over and over at how squaddies go way, way, above the call of duty for each other -- phone calls to help out during tough times, computer parts in the mail, whatever.
The squad's tag line says it all -- "Where men become friends, and friends become brothers."