I've got experience with both the Rocketfish unit and the Outlaw Audio OAW3.
The OAW3 is currently in use for my side surrounds in my living room, using a small amp at the rear of the room to power the speakers and the "wireless" unit works flawlessly. Sound is plenty good for surrounds.
The Rocketfish is in use for a zone 2 application in the garage -- again, it works just fine. It has a built in amp and the volume levels are fine for that application as well.
These are called "wireless" but you still need wires from your amp (if using the OAW3)/Rocketfish receiver to the speakers, plus a power cord, so you'll need to consider that, but as far as how they work and sound - no problems.
You could also use some powered monitors if you wanted to forego a separate amp (or just try the Rocketfish or powered Outlaw OAWA3 unit).
If you're looking for audiophile-quality and high SPLs, then these probably aren't your solution, but for surround duty, a subwoofer, or a lower-volume, non-critical listening set-up they do fine (for me anyways). YMMV.
My personal preference is the Outlaw unit. It's smaller and I like the multiple connection options available.