I don't think weight is a plus, especially when trying to position it.
How low do you really want to go? If you're REALLY concerned with what people coin "subterranian" bass then get the cube since what you are gettinig is inaudible but you can "feel" it.
Either way that's a whole crap load of power for both subs. Is your room big enough to warrant those subs? I know of a couple of friends that purchased subs that were way to large for their space so most of that power is useless unless you feel like blowing out an ear drum.