Two different luthiers have had a go at the nut on my 339, so I don't think I'm getting string binding there. But that's a good point about possible binding at the saddles.
My 339 had to have been rushed out the door ... the bridge setup and saddle notching was done carelessly because the string spacing is way off. So it wouldn't surprise me if there is also some string binding at the saddles as well. I looked into Gibson replacement saddles to rectify the string spacing, but it's not really that much more expensive to just get a new (and potentially better) bridge.
I ordered a TonePros ABR bridge this week, and I'm going to get the saddles notched and radiused properly by my luthier. I don't know who puts on the bridges and notches the saddles in Memphis, but mine must have been a Friday afternoon job.