With the current pricing going on the Polk Monitor 60s I was planning on buying 2 for the front mains, 2 for the rears and a CS2 for the front center along with a sub (looking at the Lava LSP12). I was planning on using the 60s for the rear as than I do not have to worry about mounting 30s or 40s anywhere and the 60s are actually significantly cheaper than the Monitor 50s right now. Is there any downside to doing this? I realize the rears will not be truly utilized but besides that? I also plan on listening to music probably 60% of the time so thought it would be nice to have the 60s surrounding the room when doing that rather than having 30s or 40s in the rear. Ideally I would like Monitor 70s for the front and 60s in the rear however the 70s are priced at $299 each but I have until January 30th to return the 60s so I will keep my eyes peeled. The room width ranges from about 10 feet to 13 feet and 25 feet long and the TV.