I'll try taking off the amp to look when I have a chance.
Regarding sound, I'm not that informed about sub woofers and have had limited experience. I have this sub with my Monitor Audio RS6 and the MA already has really tight and fast bass. My last sub was a Polk PSW12, which was pretty bad after countless hours of setup and relocation. It just sounded superficial and didn't blend well regardless of how I changed the crossover settings.
The Swans sub is tight and has plenty of power, I keep it at 1/3 power and the receiver's Audessy settings still tune the level down.
The bass sounds controlled, tight and fast. From my experience the good subs and location do not rattle but provide deep bass that seems to penetrate your body. At higher listening levels this sub does just that while at lower levels it doesn't "thud" out but still gives me good bass and punch. Granted the MA speakers provide really good bass for me already. I haven't had a chance to listen to any soundtracks with super low frequencies so can't really comment on that.
I did watch Transformers 3 and the soundtrack was a great way to test and show off the sub; which did a remarkable job. Even at the lower frequencies and scenes with lots of sound effects the sub blended in very well with my speakers. I also watched a few familiar movies to compare and I can say the sub is awesome.
I also compared it with my cousin's Polk Audio DSWmicroPRO 1000 on my same exact setup and can say that with limited comparisons I couldn't tell the difference in most scenarios but under some cases preferred the sound of my larger sub as the bass seemed deeper.
I'm no pro so please take my comments with a grain of salt and as my opinion only.
Regarding price, I paid a lot less than you have quoted so maybe the value of the sub seems much greater to me.