My 07 Eddie Bauer came with the so called premium speakers. I'm planning to upgrade the stock speakers and hopefully get something that has a little more bass. I don't plan on installing an amp at this time, maybe later. I was looking at Kicker KS680's, which have pretty decent customer reviews, but some say they lack bass.
You know, people have told me that the factory system in my 07 Expedition sounds great and say there is no need to upgrade. I agree, it sounds decent, but I would hate to swap out stock speakers for aftermarket and not notice a difference.
I will disagree regarding the bass. The bass on the Infinity components I installed is incredible. Almost too much. Really impressive considering they are being pushed by a head unit. I would love to see them with a 50 watt amp.