Like every brand, they have occasional issues. I’ve had a BHK pre, BHK 250 amp, Stellar P3 power regenerator, M1200 mono amps, and a P300 regenerator.
The BHK preamp and BHK250 both had issues that required a trip back to the factory. The BHK pre’s first repair was a reasonable $300 flat rate and included new tubes and a new remote as well. After the BHK pre’s second failure PS Audio repaired it for free.
After many years the capacitors in the P300 leaked and I had Cullen Circuits rebuild it (before they went out of business.) Worked fine since although retired from service now.
The P3 regenerator and M1200 amps have been rock solid and reliable after years of service.
From reading PS Audio’s own forum posts, one gathers they’ve had occasional issues with being unable to repair certain older products that used outsourced parts that were no longer manufactured. This problem isn’t unique to them, any manufacturer can have similar issues.
While they might not be 100% reliable (nothing is) they provide reasonably quick repair and stand behind their service. That’s worth a great deal IMO. I've have poor service related interactions with some manufacturers.