Sweet!! A new setup to look at
You've got a nice start & yes the PB-12NSD will make a very large improvement in your system!!! Your going to enjoy that!!
Little advice...I noticed that your left speaker is a little further away from the TV than the front right speaker. I would bring the left speaker in towards the TV a bit so that the Left/Right are equal distant apart. That would help with any side reflection your getting off the wall with the left being so close. This would also free some room up to place the new sub in the front left corner, outside of the left speaker. With the corner placement you will benefit from more boundary gain. It will most likely have more impact for you if it's in that corner. You won't have to turn it up as loud for it to sound good & this will probably actually bother the other tenants less. The GRAMMA will help too!!
Make sure that after you run Auddessey go in & change ALL speakers to Small & with a crossover of about 60hz-100hz. 80hz should be good but see which sounds best to you!!! Before you run Auddessey, have the volume knob on the SVS between 35%-50%.
This should get you setup pretty nicely!
Thanks for posting the pics, lookin good!!