It's also quite big, a 42 units rack will get quickly filled
I was thinking this as well. It certainly does not look as "rack friendly" as they were originally claiming, especially if the PSU is not housed within the unit.
Well, there is a solution for the lack of design to fit in a rack:
Technical details
Rack capacity: 2U
Maximum weight (capacity): 22.6 kg
Colour of product: Black
Source data-sheet: Icecat.biz
Other features
Width: 482.7 mm
Weight: 2.6 kg
Size: 406.4 mm (16 ")
Package weight: 3.3 kg
Height: 88 mm
Depth : 406.4 mm
Read more at http://www.extak.com/catalog/25295/StarTech.com-2U-16-inch-Universal-Vented#qAWKhfPCXX33RWBx.99