Can't believe I'm doing this, but I'm going to step in here and defend Logitech. First of all, I appreciate and desire good sound quality. Secondly, most of the time speakers sound shit because the source is terrible. Good speakers will never make 128 Kbit mp3 files sound any good.
Anyway. Before I left home for uni, I used to listen to my music through a pair of vintage Celestion ditton 44 series ii's, hooked up to a Marantz amplifier. They sounded absolutely fantastic.
My housemate has a set of AE 2.1 speakers that the OP bought. They sound great (the subwoofer has a wooden cabinet FTR). But like most 2.1 systems with such small satellites, there is a degree of seperation between the lower end of the sats and the upper end of the sub. The sub has to produce a lot of midrange to compensate for the small satellites, which is OK if you have all three speakers reasonably close.
I didn't buy a set of AE's though. I decided to go for the cheaper Logitech Z2300's. TBH I am happy enough with them, they are great for uni. The subwoofer is very powerful, too much so in fact on the default bass setting, but is fine on 1/4 or so, and the satellites are suprisingly good, even without a tweeter. They do however lack any substance in the lower midrange, and the set looks quite cheap and tacky if I'm honest. But play a good quality piece of audio through them, with the sub on low, and they sound pretty close to the AE's if I'm honest. They also make for great houseparty's when you wanna get obliterated, as they go very very loud - louder than the AE's. Can't really argue with that for 30 pounds less, especially when you're a student.
Logitech do go down the route of marketing BS to an extent, and the cheaper systems (x-230 etc) are cheapy rubbish, but I think the Z systems are pretty good value.