"All of A.Z.'s tunes fail eventually and only he can fix them" Where do I start with this? I have owned 5 A.Z. tuned guns and have chosen to have him redo some stuff on two of them, but neither of the guns failed. I just decided to have him tweak stuff differently than when I originally purchased the gun. Out of those 5 guns from A.Z. I still own 3 of them and those 3 guns have never failed over the 10 years that I have owned them. Now to the second part of your statement, "Only he can fix them" Absolutely not true as Martin Rutterford can fix and repair these as well and turns them around in a very respectable and reasonable time.
I have chosen to send a couple of these guns to Martin for "preemptive maintenance" I.e. a total reseal and some hammer work on one of the rifles. Note: Neither one had come close to failing when I chose to send them in, I just thought it would be prudent to reseal the guns after 10 years of use.
Finally, that is why I started the response thread off with "You forgot an option" which I mentioned as buying a new R.A.W. rifle. They are really close to a tuned gun out of the box from the factory and appear to be built as well or better than all the Rapids of old.
I am glad you like your F.X. rifles and respect your choice of guns but in the long run I would put my money on the durability of either of the other two options we have been discussing.