Which is better: entry-level receiver or older top-of-the-liner?

[reubelim]

Hi: Have my eye on the Onkyo 605 receiver to go with my Panasonic HD-ready 50-inch plasma tv and Pioneer up-converting dvd player. I also have a blu-ray drive in an HP Pavilion notebook which I connect directly to one of the Panasonic's 2 HDMI ports. Question is, should I go for the Onkyo (HDMI ports, HD sound processing) that I can afford or for a bit less should I get my friend's Yamaha AX-1 receiver which is an older model without HDMI or the newer HD sound processing but which has more power and seems to have other very impressive specs befitting a top-of-the-liner of a few years back? I am also eyeing my friend's B & W 604s and center to go with my existing AR-15s (to be used as rears - I now use them for fronts), small Yamaha sub and Sherwood surround speakers, and I have heard I would be better off getting a more powerful receiver like the AX-1 rather than the 90 watts per channel from the Onkyo. Right now I am using an old Yamaha entry-level receiver (claimed 70 watts per channel) which does have DTS and I have to crank up the sound a bit to drive the AR-15s and the Mission center I now use. I use my setup for movies primarily, perhaps because the sound as of now is a bit thin for music, but I do want to also listen to my music on a new setup if I could. Would also appreciate an opinion on whether I should get the older B & W 604s (these are the old ones) or just get the newer good models I can afford, which would have to be bookshelf size. So many questions...be well all!