Haha it's not the weight it's the size!!!
Not only is the enclosure pretty massive, it is also double boxed to protect it from shipping damage!
You really do need to mock it up out of cardboard before continuing. Thats what I did & so have many others when deciding on any sub in this class. The dimensions are on their site. Just cut a piece of cardboard that represents each of the 4 sides plus the top & bottom then tape them together to for the box. You may be suprised at the size.
But remember!!....we are dealing with the laws of physics when it comes to subwoofers. There is no getting around that!!! So in order for a sub to play low AND loud AND at a reasonable price, the enclosure WILL be large.
For your room, the VTF3 MK4 would be more than enough honestly. It's just a matter of knowing you have the best they offer for not much more money & knowing your future proofed, that you'd want to get the 15H. Even the VTF2 MK4 would be plenty haha.
That's really why you should try to get down to the demo room if any way possible.
I have a Chevy Express work van that I picked my VTF-15H up in. I laughed at how much room it took up in the back. So much that I took a photo.
No Hond Civic could dream of gettin one in her...(that sounded weired)