I have a couple of Firestone pin-locks and the following are all ball-locks: a Challenger VI, a Challenger (that's not the real old style with the odd shaped lid), an old Challenger (with the odd shaped lid), and 5 Cornelius.
All of my ball lock Firestone/Challenger kegs have plastic gas-side dip tubes that are not made anymore. Also, the typical o-ring kit (from say AHS) doesn't have the proper seal/o-ring for inside the posts (the outer post o-rings and lid o-rings fit all my kegs). I don't like them just because of that.
All 5 of my cornies have metal gas dip tubes and the o-ring kits (such as the ones from AHS) fit. I like them because of that so I always try to get cornies.
My 2 psi.
