Congratulations on your SB13-Ultra purchase SBO5007. I'm sure you'll absolutely love it. I purchased mine, oh, I guess it's been a couple of months ago now. Time flies. I find it's an absolute marvel for music, so I use the Ultra 100 percent for music in my stereo system. I liked it so much I wrote two extremely long-winded reviews, one on Amazon.com and the other on the SVS website. I'm sure it bored anyone reading them, but when it comes to audio, I tend to go on and on....
As far as some of the questions concerning break in periods, my Maggies took a good 6 months to break in. My BIC subwoofer, I'd say a little over a month to find its full legs. The SVS sounded pretty good right out of the box, but needed a couple of weeks to pound deep enough to highlight multiple noises throughout my house (heck, I found another painting rattling just yesterday).
Music area: Magnepan 3.6, McIntosh MC2205 amp & C48 preamp, SVS SB13-Ultra, Oppo BDP 95, dbx 3BX, and assorted equipment.
Movie area: EMP Tek E5Bi (were rebadged to R5Bi), RBH/EMP Tek R55Ti, PSA S3000i, Denon X2000, Oppo BDP 83.