Pros: Great sound for its price, durable, easy to assemble.
Cons: Front speaker cables may be too short, sub is exposed and may be prone to accidental damage
I have had these speakers for almost 6 years now. Downgraded from my old Logitech Z680. The sub of the Logitech Z-680 had a buzzing sound within a few months of use that forced me to set the bass volume to less than 10% (although it was sufficient enough for decent bass). Until now the X-540s have not shown any signs of aging or sound deterioration. This considering that the speakers have been dropped a few times as I relocated 3 times and also had my little brother's toys thrown at them occasionally causing a minor dent on one of the speaker grills, it still performs well after 6 years. No distortion, and no discernible deterioration of sound quality. At least I didn't notice it. The sub doesn't have a grill and is exposed, although it is still intact since it always faces the floor and I often keep it in enclosed spaces.
The speakers are ideal for a small size room. I never had to go over 50% volume. The bass, despite its small size is no slouch, I had to set the bass to 25% max otherwise the neighbors would come knocking. The speakers can be wall mounted easily as well.
These speakers are perfect for the price. My only gripe with it would be the cable length and the inability to replace the cables. I had to use extension cables if I wanted to set the speakers a little further away from the sub. I don't expect the best sound from these speakers and therefore don't think anyone would want to replace the cables as it might have minimal positive effect at best. But still the experience I've had with it was positively great.
I also like the fact that I can control the main volume and bass volume through the extended dock.
Definitely better than the Z506 (which is "supposedly" an improvement model). I don't like the fact that the Z506's volume controller is on the right speaker. This limits the positioning of your right speaker. Also the bass volume controller is behind the bass, which would be an inconvenience for some, especially for those placing their sub inside a cabinet or enclosed spaces. Not to mention less drivers and are priced the same or higher.
I would purchase X-540s again if I could, and would definitely recommend these to anyone interested in a budget 5.1 computer speaker system.