Disclaimer: I am the developer of the TrailPix. My intent here is to add to the conversation that is occuring and answer your question in the best way I know how to.
I've just added a FAQ for this very question, here is how it reads:
What is the load limit of TrailPix?
The short answer is that I think anything more than a 4 lb. camera is pushing it, mostly due to the ballhead, and then for something in portrait. But, for completeness, here is some more information:
I figured a way to add weight directly to the center of the ballhead, and here are some approximate weight limits:
1) Universal made with (3) trekking poles: 30+ lbs (Probably significantly higher)
2) Universal made with (2) trekking poles and accessory pole: Approx 10-20 lbs. (limited by flex in the accessory pole)
3) Custom made with (2) trekking poles and accessory pole: Approx 20 lbs. (limited by flex in the accessory pole.)
Since these weights are for load directly over the ballhead, they aren't terribly meaningful, but they are probably equivalent to what you might see spec'ed out for other tripods.