It looks great! It's on my short list to make, I'm looking forward to the finish pictures.
I like the looks of this one. How big did you make it? Any chance of a few more photos, particulary of the leg and strap connections?
Looks darn functional to me.
. As for filler, I did use silica, I think it is silica, white fluffy stuff that you dont want to get in your lungs....
I heard that when ever you use filler in epoxy, it actually reduces its strength... I might wrong.