Has anybody had any reliability issues with VAC amplifiers?

I owned a Phi 300.1a for six years or so without issue. VAC's Sentry Circuit was triggered a few times, shutting the amp down when a tube went bad, preventing possible damage and worse. I would not own this amp without that safety feature. I believe all the IQ amps have it, so no worries.
I still have the matching Phi Beta preamp, which chugs along like a champ without any problems.