which speakers are better?

Howdy, I'm upgrading from my home theater from a sony HIB and looking at polk speakers. Im sticking around a grand for receiver and speakers. So naturally im looking at the complete T-series set up with an onkyo tx nr757. But on Amazon I saw a onkyo tx nr656 with polk TSi speakers bundle that fit my budget as well...Which speaker line is better TSi or The t-series? I cant seem to find much info out there to compare the 2 lines.