One recent personal data point here. I bought a pre-owned DRS Classic (.22 cal/600mm) from UA towards the end of September. While I don't know its history or what the original owner did with it, it just didn't shoot well - General poor accuracy with 18.13's and pretty slow muzzle velocity. A little better accuracy with 15.89's, but ES over a 12 shot string was like 40 fps (and that was after burning the first 2-3 really low velocity shots).
Contacted UA for warranty service on 10/9. Same day response from them with a service ticket number. Next day they provided a paid return label. 6 days later (4 business days) I received notification that my gun had been received, and that current lead times for repairs were in the 3-4 week range.
23 days later I received an email that the no-charge warranty work had been completed, and a couple of days later I received the DRS back. They had replaced the reg and the valve components, and since I had mentioned it, had tuned the gun for 18.13 gr pellets.
For someone new to our sport, this may have really seemed to be a long time for warranty service. Especially if it was their only gun. I felt that the communication and turnaround from FX's US Service Center (now Utah Airguns) was great. And all communications were very friendly, upbeat and apologetic - even though I was not the first owner of this gun.
My single data point says that Utah Airguns is doing a very good job as the FX US Service Center.