I own Polk RTi8s and Axiom M22s. I have not listened to the RTi6's. The RTi8 is a better speaker than the M22. It is also a tower speaker and a little more than twice the price if you pay retail ($840). However, at the Polk website some of the reviewers of the speakers talk about getting them for under $400 a pair on clearance. The bottom line is that Polk and Axiom both make great speakers and give you about as much as you can get for your money today. If I were you and I could find some RTi8s on clearance somewhere I would do it - unless space is an issue and you really want bookshelf speakers. RTi6s and M22s are both great options.
P.S. What is your first language? You do fine in English.
