I was picking up some F to RCA adapters at Le Shaq when I noticed the 550's were on clearance for $40 each. The hardware junkie that I am couldn't resist, and with the 30 day return policy, I have nothing to lose. These will be my surrounds, but I'm burning them in as mains. If you are curious, I'd say go get a pair. They sound pretty good straight out of the box, but 6 hours of continuous play back later they got better. Lower mids lost their edge and the speaker got smoother. Reviews say stuffing them improves things, so I did. It seemed to help lower the bass cutoff. I haven't plugged the port yet, but I'll try that too. The crossover is a cheap affair - one cap and one inductor, but the sound eminating from that tweeter is pretty cool. 5 for $200 would make for a pretty interesting HT kit.