Is computer audio a bust?

In recent months, I have had several audio acquaintances return to CDPs claiming improved SQ versus their highly optimized computer transports (SS drives, external power supplies, etc, etc).

I wanted to poll people on their experiences with computer "transports." What variables have had the most impact on sonics? If you bailed on computers, why?

I personally have always believed that the transport, whether its a plastic disc spinner or computer, is as or more important than the dac itself and thus considerable thought and energy is required.