well based off a standard pci bracket length of 4.75", you can look at this picture off the auzentech website and figure the length at pretty close to 6.7". so, i guess that means it would not be much longer than a mini itx board at 6.69"
I am considering purchasing one of these cards in a few months when i get my carpc set up, and I was worried about the length as well. Hopefully the driver issues will be corrected by then.
