Yes they work really well. Unfortunately I had one point inside that popped when I pulled on the zip tie, but I believe that was due to the one of the anchor points on the tool box not being set correctly. But I can easily fix.
The strapping is almost complete. I am making them adjustable but had a sewing machine mishap. Strapping and weathering will be complete this weekend for trooping. I'll see if I can wear it for 4+ hours at a toy show.