I find towers completely unnecessary for surrounds. My setup will be used for less than 10% music, so I'm more concerned about HT performance, and towers would actually be detrimental in that aspect. You shouldn't be able to locate surrounds, hypothetically speaking, and if I had towers back there I would definitely know where the one closer to me was. Maybe if I was the only person living in my house, and I only had to worry about my sweet spot seating, towers would work, but I need seats from wall to wall.
Yeah, XLR cables... I am going to look around because outlaw's seem overpriced. I am so terrified of the horrible, horrible ground loop that I may cause (3 or 4 power outlets, 2 cable feeds, 1 antenna feed, sounds like a ground loop waiting to happen to me), the last thing I need is a 60hz hum just because I didn't use balanced cables.
Buying the proper cables sucks.
I must have been really tired or something, but last night I was actually thinking about making it a 7.1 system, and hanging a couple of speakers from my ceiling behind me. I must be crazy, but I'm still considering it. That would be about 1000 extra bucks though, I don't think it's gonna happen with the original purchase, but I'm definitely gonna do the wiring so it will be an optional upgrade in a year.
Are you planning on using the included mic to calibrate your system, or are you getting an spl meter? I'm probably just gonna try both, because I have never manually calibrated speakers before, so I'm unsure of my capabilities, but it looks pretty simple.