The hexagonal cages look nice on paper, but they often tend to be more than you bargained for such that they wont fit out any door for cleaning, they take up more space in the room since they arent square. The best cage in my mind is a rectangle that fits nicely against the wall and is longer than it is deep and goes from floor to ceiling, no stand. I think the tower cages are popular because of their good use of space. You can find the same or better cu inch in a rectangular format and it is still easy to handle.
This
hexagonal cage
with 18" x 48" panels calculates out to around 37,584 cu in of internal space.
The popular
Exel Large Tower
at 30" x 18" x 52" calculates out to 28,080 cu in.
The
Exel Extra-Large Tower
at 30" x 30" x 52" comes out to 46,800 cu in.
Use the internal cage measurements to calculate CUIN and compare possible cages and then price and usability.