I also have two WTO SwitchLug rifles. WTO built both rifles and did all barrel work. I'll echo what RussellJ said, WTO folks are exceptional people. Literally no one in the world that I'd rather do business with. They do exactly what they say they'll do when they say they'll do it. I've had them build me 6 rifles to date & I've owned another that they built, but not specifically for me. I have no plans to use anyone else whatsoever for any of my rifle work moving forward.
I have a SwitchLug rifle built on a Rem 700 receiver with a Mack Bros R700 bolt. I've got 3 barrels, 6mm CM, 6.5mm CM & 7mm SAW. All three shoot 1/2 MOA consistently & are capable of less when I do my part. Barrel swaps are quick and easy. Just a few minutes.
I've also got a 6mm CM built on a Zermatt Origin with a SwitchLug that I had built for my son. We currently only have the one barrel for it & plan to add more as he grows & his hunting expands beyond TX whitetail deer & hogs. It is also a shooter. 1/2 MOA easily.
To answer your questions:
Yes, I love the SwitchLug & WTO.
Yes, I will very likely do it again.
Literally nothing about the system that I do not like.
I have not run prefits.
Good luck!