I've owned both brands, not the particular model #s you've listed though, but I do suggest the Altec over the Logitech, from personal experience, and the fact that Altec Lansing has been making speaker systems since I can remember, they have a quality product, and will stand behind it, thats the most important thing to me.
Details, Details, Its all in the Details, If you need help, Don't leave out the Details.