Well I'm running the X-530, I think the predecessor to the X-540, and they're great for computer/gaming speakers. They're very clear and the bass is nothing insane but it definitely gets the job done, I like whatever they put in there that makes it impossible for me to blow the sub up.
Here is the side by side comparison
Brand new on the site the 540's are $139.99 and the 5500's are $549.99, so I don't think you'd see them for $250 unless it's a crazy sale item.