Pros: Support DTS and Dolby Digital PL II, THX Certified, Digital Coax and Optical inputs, provides excellent bass and clarity for all but the pickiest user
Cons: May lack some mid-range, cannot replace speakers despite the use of standard speaker wire due to built-in crossover
These speakers were the first purchase I made of higher quality audio equipment in any regard. I mated these speakers up with an M-Audio Revolution 5.1 sound card ($100) and a Digital Coax cable and have had a fantastic experience ever since when using my computer. I paid $280 for mine about 5 years ago and the price has held firm and actually gone up to around $300+ at most online retailers. These speakers offer receiver level processing cabability and are neatly bundled into a control pod that looks pretty cool. The included remote is simple and quite handy to operate the speakers - you have clearly labeled effects to use (Stereo, Stereo x2, PLII Movie, and PLII Music) - each with adjustable settings that are remembered for each effect that you use.
These speakers put to shame most HTIB systems you could buy for under $1,000. The subwoofer is a 10" long throw driver with 188 watts RMS power, each satellite is 62 watts RMS and the center channel is 69 watts RMS - coming to a total of 505 watts RMS. The subwoofer is capable of shaking the walls and maintaining a respectable balance as well - it cannot hit true lows as a dedicated home audio subwoofer can but it goes very low and for most people this subwoofer will be very satisfying. Games and movies alike sound fantastic on these speakers. I also listen to music on them and am quite pleased with their sound. They are not perfect but at this price they rival many higher cost solutions.
I have a dedicated home theater system using a Denon AVR-4802 THX receiver and at the moment a pair of Celestion Ditton 300 speakers and a 12" Eosone subwoofer and while I notice a larger dynamic range and soundstage with them, the Logitech Z-5500s are still a pleasure to listen to and were a mere fraction of the price of my home theater setup. In computer speakers they are bar none the King of Speakers and they oust many HTIB systems costing twice their price. Whether you're a budding audiophile or a seasoned veteran - I think everyone can appreciate the great value the Z-5500 speakers offer. Give these speakers a shot, you won't be disappointed.