In the past I personally owned a Phase Linear 400 series 2, H/K Citation 16, and an Onkyo M504. Each amp failed for one reason or another within a 9 years span.
A small correction, the Phase Linear was a pro sound reinforcement amp, not a high-end amp. They did sound different from most PA amps of the time however. Those who like the Phase Linear sound are very dedicated to keeping these amps alive. However, they were/are not known for reliability; I assume you know the Flame Linear nickname for them.
I have A/B'd pro sound reinforcement amps v. high-end amps and find that PA amps do not do well in the comparison. The owners and engineers of recording studios and mastering studios come to the same conclusion and don't use them in their work either.
PA amps have gobs of power, the ability to transfer lots of current, and the modern versions are bullet-proof. They are wonderfully designed for their purpose and have been maximized for this role. They are an excellent buy if you want lots-o-watts on the cheap.
They are excellent for those that enjoy the sound of live amplified music as these are exactly the amps used to create this sound. This sound is distinctive and characteristic of R&B and live rock venues. If this is your music I would recommend trying a PA amp.
Unfortunately, they are not good at reproducing subtlety and nuance - neither dynamically nor in frequency complexity. They do not capture the timbre and harmonic complexities of unamplified acoustic instruments, nor the ambient sound of the space in which such instruments are played. Which is, of course, why they are not used as reference amps in studios. It is also why I don't like them for music reproduction.
Some people love them even for listening to unamplified acoustic however. I have no criticisms but don't share this opinion.
If you recall the sound of the spec wars Japanese amps of the '70's you know the basic sound of a PA amp. Clean in a brittle way, but muscular. Perhaps PA amps also have high TIM as the SS amps of the 1970's did.
There is one exception that I know of: Bryston. They make amps that both sound good and are also used in sound reinforcement applications. I don't know why they are different.
As we all have our own priorities I don't dismiss their use in a home system. Some people love the sound of these amps. They are lucky; they do not have to spend much on amplification to get the sound they enjoy. This is pretty cool.