apartment subwoofer?(svs, hsu, etc.) help!

[Colglizity]

Hey folks- I live in an apartment on the third floor and towards the middle. After the rest of my DefTech ProCinema 800 that I'm piecing together arrives, my Yamaha subwoofer (10"x100watts) is the only thing holding my system back, not a bad sub by any means, but I'm really missing out on the real low-end levels that I hear when I visit my Dad and his SuperCube II. My questions are: (1) just how bad would my neighbors hate me if I were to step up to something a little more powerful? (2) Do the lower levels pass through walls as much as the big "thumps"? (3) Is it worth it to buy a subwoofer of this caliber where I'm living now, and if I were to move to a condo later with shared walls? I'm looking at the SVS 25-31Pci sub right now and it has me licking my choppas... thank you