I am planning to build home theater and still researching. Do any of you guys compared these 3 surrounds.
Axiom QS8 (http://www.axiomaudio.com/qs8_gallery.html#)
Rocket RSS300 (http://www.**********/products_product.php?section=speakers&product=7.1)
Aperion 534-SS (http://www.aperionaudio.com/product/Intimus-534-SS-DipoleBipole-Surround-Speaker,21,30,111.aspx)

Budget for surrounds: $500.

Right now, I am using Athena Point5's for surrounds. Planning to replace mains and center too.

Choose your surround based on what you would want for your mains and center to be. In other words don't mix and match speaker brands and series if you can avoid it. Speakers that sound different from each other will degrade the overall HT experience. What I would do is listen to the main speakers you would eventually want to get and get the matching surrounds. Then later buy the mains and the center. I know that quite a few people on this forum mix and match speakers. It doesn't make it wrong, just less picky or don't have the money to upgrade the other speakers which is all fine. I used a different series speaker as my surrounds due to money and it sounded pretty good, but when I got the matching dipoles I was in heaven.