I had the Z-340s for about 3 weeks. I was initially very impressed with them considering their price.
My initial complaint was that the speaker wires are all pretty damn short.
After listen to music on them for a week I began to notice all the songs were off. That is, the bass reponse was far too harsh. Any song with decent base was vibrating the floor even at low to moderate volume. You might think this was a good thing, but it was off...too much bass. Twice my neighbor came over and complained my music was too loud when I didnt even have it up loud. The bass was just travelling through the floor and pissing them off. The music just didnt sound right...I could tell the bass was coming from the floor. For $50 I was trying to deal with them. I even turned the subwoofer volume all the way down but then all the music sounded nerfed. They IMHO cannot produce a balanced sound. They are either too bright or too muffled and I cant deal with bright so they just sounded muffled to me and were pissing off my neighbors.
FWIW...I do consider myself to be a moderate audiophile. I own a killer Denon based home theater with Polk speakers that cost ~$450 each. Not bragging...I just like my music.
Anyway, I just couldnt deal with the overwelming bass at low volumes so I took them back.
I got a $100 gift card to Best Buy, went there and noticed they had the new Altec Lansing 621s for $179 with a $30 rebate. I compared them to the Klipsch 2.1 and 4.1 and the 621s just own the Klipsch. The Klips were REALLY muddy which is a complaint I have heard elsewhere. I am really happy with the 621 sound...listening to The Crystal Method right now and they sound perfect. The bass is all there and the floor is not vibrating. They produce a nice clean even sound. I fully suspect that when the reviews come in, the 621s are going to be declared some of the best speakers on the market.
However, they were $150 and I had the extra $100. I did listen to the Altec ATP-3 that was there and they sound very decent to me. I was going to buy those but I got the Z-340s because of all the hype Logitech was getting which to me is most likely because of their low price. If I didnt have the extra $100 I would have bought the ATP3 which if you watch for sales you can find for $50.
In hindsight, the Z340s are really cheap. The wires and connects are cheap and too short. The power converter is cheap too because when certain lights were turned on and off around the house I would hear a pop in the speakers. My el cheapo speakers prior to the 340s didnt do that and neither do the 621s.
Basically, I recommend the Altec Lansing ATP3 for lower end (~$50-75) and if you can save up go for the 621s because they produce a slick sound.
Cheers,
Nova
p.s. when you but those 340s online for ~35 and pay the $10 for shipping they are similar to the $50 you can get the ATP3s for if you watch the sales.