I'm looking to sell my Bose Companion 3 set and get a the Logitech Z-5500 5.1 speaker set. What do you think? Will I notice a difference in sound quality? I'm more focused on the actual sound quality of the speakers as apposed to how loud they go or how much bass they have. Also, the Z-5500's have a digital optical out port. How would I connect this to my MacBook?