Dick said a mouthful.
"Properly reworked" is the key.... I bought a used 700 from Borden's Accuracy that Jim had reworked himself and it really does shoot lights out. But understand that when Jim Borden "reworks" an action it's seriously improved. Jim doesn't just chase the threads and "true up the face" he changes the timing and tolerances throughout. I bought it as a platform for a Hunter Benchrest gun and it was cheaper than a custom action, only because someone else had paid to get the work done and I bought it 2nd hand at a discount. Incidentally I have several other "reworked" 700's and they DO NOT shoot like that. Jim's timing and trigger work truly is magical. BUT, When I or my heirs go to sell it it will be worth the price of a used Remington 700 action.
and therein lies the rub....a custom action will hold it's value.
IMO
al