I could go into one of my detailed responses, but let me break it down for you:
VP150 has about $0 resale value. I know, I still have mine sitting in a closet on a shelf doing nothing because the VP180 is AWESOME!
I was a Pioneer Elite fan for a number of years, but switched to Onkyo and absolutely love it. Not a fan of Marantz. Not that they are crap, just better performance/price can be had with Onkyo/Denon.
If your room is only 17 feet deep, go 5.1. Sure, wire it up for 7.1 (or 7.2), but spend the bucks elsewhere.
I went 7.2 (as of today with the addition of my 2nd sub), but anyway, that was because my room is 24 feet deep and has 2 rows of seats with a few feet behind the back row even. I can't say that I am blown away with the extra 2 channels, but I am glad that they are there since my room is fairly deep.
If you really want some WOW factor, get a newer model center channel, new receiver, and then spend some money on acoustical treatments in the room (this is not soundproofing - two total different subjects). You will really like additions of bass traps and acoustical panels at 1st reflection points. Acoustical panels are next on my 'must do' list. In fact tonight I am going to find the 1st reflection points and tomorrow my fabric samples are arriving. I can't wait to get those done.
Take any additional money left over and get bass shakers, a separate amp, and a popcorn machine. Those will really add some wow factor.
Ok, so it was a longer reply, but I need to run... Literally. Just 4 miles tonight. Then calibration time. YAY!
M60s, VP180, VP150, QS8s, SVS 20-39PCi, HTPC, JVC RS45, Onkyo TX-NR709, Shakers