Jon,
before you buy a new or used BL2, ask your dealer or somebody else to pass you the BL2 for a day. Eihter you love it or you hate it.
You only could change between very limited options (there is no switch for frequency, level, bandwidth like most subwoofers). The BL2 will ruin your listening attitude for music, but for movies its a "killer".
If you love a subwoofer, better go for the PV1 from B&W (it is B&O-style) or a smaller Velodyne (microvee). Both are much better for music than the BL2.
No, the BL2 is not a bad subwoofer. But it is sometimes a bit slow and heavy and it is maybe a bit hard to adjust both for music and movies.
BeoVision 8-40, ATV2, BeoSound 4, Front BeoLab 9, Rear Beolab 4000 MKII, Beo 4