Yes, you should always listen in the end, but specs if you understand them as I outlined above, allow you to weed out the rubbish or unmatched stuff before you spend the bucks, no matter how the wow factor looks externally.
To dismiss specs is just buying on hope and crossed fingers. To do the homework on specs will save you time and money selecting the right matching equipment to start with. Then listen and decide on the bunch that is spec'd right for your system, instead of buying total mismatched stuff.
Cheers George