All 3 of these manufacturers' loudspeakers sell very well, regardless of the perceived reaction from an advertisment or two. They also have completely different marketing approaches to the masses so you simply can't compare them line by line.
Polk Audio tends to have closeouts more often than the other two, simply due to the volume actually produced and marketed commercially.
I haven't heard a DefTech I've liked until the new Mythos series. It's pretty tight and I'd wouldn't turn down a pair at all. Sandy G has a smoking setup.
It's business man, and everyone does it differently.
That being said, I love the Paradigm Studio series and believe the top end has more clarity than the Polk competitor, the LSi. The LSi is just more laid back in presentation, plain and simple. You can't make a speaker to please everyone, that's why this hobby is so much fun.....you get to listen to all kinds of things.
Buy what you want folks but in the end, don't short yourself....listen to everything.
Regards,
Mark
Polk Audio CS