all reviews seem to be good and it's below £50... why spend 100 more on, for example, the Logitech Z-5500 THX Certified 5.1 Speaker System (both on OCUK. i know nothing about speakers and want a 5.1 system (i think)and wondered why you would spend almost 200 when 45 is possible?alos what does the "W" of the speaker mean, i know it means watts but what is a reasonable number for each type of speaker (satalite, bass etc.)