I bought 2 right off the bat it's a big big floor plan and I like they're upgrade program so I bought 2 and figured I'd trade up if I needed more headroom. I like your using the 3 bookshelves as your fronts. I use 3 SVS prime towers as my fronts. This has worked way way better then any center channel I've ever used. I'd have gone bookshelves but the size of the room I figured I'd need towers. I know a lottof people don't have that kind off space on setup but I did and audioholics has a lotto f good articles on why this setup sounds so great. In regards to loudness getting 2 subs isn't always about the loudness. I was surprised at how smoother and better the bass was over a much broader area I was also able to get to the loudness I like without pushing the subs as hard which saves wear and tear on your sub and it's amp. And it never overpowered my mids or highs in fact because the bass was cleaner it made them sound better. I'm spoiled now I'll never go back to 1 sub in fact my goal know is 4! Seriously!
. So if you can get that 2nd sub I say go for it bro I love mine!
