I tried to post a review of my Z-2300s on Newegg, but they didn't put it up yet (or, maybe they never will, like they do half the time):
4 out of 5 stars
First off, these are the best computer speakers I've ever owned. The subwoofer box is massive. The online pictures are very deceiving. However, bigger sub boxes generally sound better in my opinion, so that's definitely a plus! Just wait until you get your set--you'll be surprised at how much larger it appears in real life.
I'm an audiophile on a budget. I have an Audigy 2 ZS often paired with my Sennheiser HD-280 Pro headphones, and I've invested a lot more money than I should have on other sound systems before. Therefore, I'm going to be fairly critical of the output. With that in mind, please continue.
My initial impression, the standard Windows XP startup sound, scared me. Right off the bat, I noticed a lack of highs. I started playing some music and confirmed my first thoughts. This set feels like mostly anything beyond 5000-6000 hz is missing. I know it's there, but it's not the crystal clear, precise treble sound I'm accustomed to hearing from a set of nice components. The Z-2300s do NOT have dedicated tweeters, thus, I can't be too far off the mark here. The 2.5-3" drivers in the satellites do pump out plenty of sound, though. I'll rate the high-end response of this set at 3/5 stars.
Midrange and bass frequencies are exceptionally powerful for a $110 set of speakers. I've not yet turned the speakers beyond about 55% volume, but the subwoofer is able to shake the house. The bass is very tight and responsible, and most importantly, the bass is definite. I've heard too many sets of speakers that simply make NOISE. The Z-2300's subwoofer doesn't make muffled, boomy noise; it makes clean bass, as I expect. 5/5 stars for the low end.
Next, the SNR is could be better. I expected much more from a SNR of ">100db". When the speakers are on, I can't hear anything unless I put my ear up against a satellite. However, if I plug my Sennheisers into the headphone jack on the Z-2300's remote control, I can hear faint amplifier noise even with the Z-2300s turned off. With my headphones plugged directly into my Audigy 2 ZS, the signal noise is too quiet for my ears to detect thanks to the card's 108db SNR. I'm guessing that Logitech's claim of ">100db" is correct, and that I'm used to the clean 108db SNR of a direct connection to the sound card. So, 4/5 stars for the SNR. Don't worry too much about this; search for Sennheiser HD-280 Pros, and you'll understand why I'm able to notice the noise (closed cups). I didn't even hear anything from the Z-2300's satellites until I listened for noise after hearing it from my headphones.
One final thing: cable length. I wanted to put the beast of a subwoofer in the corner of the room, which is only about 8-10 feet from my computer's tower. However, the fixed cables on the satellites are far too short at about 5-6ft in length. That limitation prevented me from placing the subwoofer where I wanted it. The good news: they're standard RCA plugs, so you can buy extension cables from Radio Shack if you want. I'll give Logitech 4/5 stars here for not using standard speaker cable clips and speaker cables like Klipsch.
Enough with the critiquing...
Music sounds very, very good for this price range. After about 12 hours of Half-Life 2, I must say I'm highly impressed. The Z-2300s really add depth to the game play. Vehicles and weapons sound powerful and realistic now, and the subwoofer creates some nice force feedback When the adrenaline-intensive music in HL2 kicks in, the Z-2300s make the scenes twice as exciting as my Sennheiser headphones could do.
I've heard the Klipsch ProMedia 2.1 set as well, and as Dan said, the Z-2300s own them. Go with the Logitechs.
Overall, I'd like to give this set 4.5/5 stars, but I decided to round down because of the short cables. For the price, the Logitech Z-2300s are an astounding value. Unless you'd like to spend over $300, get this set.
Edit: It looks long, but it's 684 words. Newegg says up to 1000 words.