Some others will most likely jump in here...Personally, I have not spent a lot of time with Polks. The Axiom 50's have been called slightly more laid back than the 60's. The Axiom 60's and 80's are very detailed and neutral in my opinion. They will faithfully reproduce the CD/DVD your listening to, that being said, if your CD was recorded poorly, the Axioms may recreate those flaws. However, good recordings sound fabulous. Some speakers that are really laid back will hide/muffle these flaws. For me I wanted speakers that accurately portrayed what I was listening to, not cover it up.
Where do you live John? Have you checked the Axiom "Audition" thread at the top of the "Hearing Things" forum. There may be someone on the map or list willing to let you have a listen in their home.
Randy