On a JTV-69, yes, right, the tuners are locking. So is the Trem Bar, it is internally threaded so it screws into the bottom of the bridge, and the set screw to make the Trem Bar Bushing Collar snug a the top of the Collar Bushing. It is firm at both top and bottom of the Trem Bar. The locking Trem Bar has been on these JTV-69's for quite sometime now.
I don't "dive bomb" much, but when I do, it works pretty good on the 69's I play.
I understand Dave's trepidation regarding Floyd Rose locking systems, more finer adjustment points, don't worry about it, like everything else about guitars and guitar playing, it takes practice. You get used to it. The Graphtech Floyd Rose bridges I've experienced on the JTV-89's are pretty solid.
And I have a 69 and two 59's myself. The locking Trem Bar on the 69 works good for me. Two different locking systems (on the 69 and 89), both pretty solid. Works for me, I like them.