In any thread where you ask for a comparison that includes a Sony product you'll get 9348 retards who pick the opposing item because of their experience with a whole one or two of their products, which generally aren't even in the category you're refering to.
I find that Sony generally does well (not excellent) in most of the audio field. I won't say they're better than Pioneer, because I don't have much experience with them except for a very old component system. I can tell you're not going for an elite-tastic setup to extend your ePenis, so I think either choice would probably be suitable. Seeing as your receiver is a Sony, then I'll have to finally suggest Sony. Of course speakers are generally universal, but I like to know that I have most if not all of the same products from the same manufacturer in a setup.