I haven't heard the newer ones (because no-one buys them... //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif ); although, I did once have one almost 4years ago, and it sounded poor. From what I'm hearing the new ones still aren't worth a dime, and it's best to spend money on something you will like rather than feel like you made a mistake and/or just end up spending your money on something else.
Sure the Sony sub will add sound, but not as good as many other subs. The Sony subs aren't worth the money either.
What price range you looking at?