I won every single challenge (including IC). My inventory is full of shirts and emblems - rewards from this wins:

Click image for larger version.  Name: shirts.jpg  Views: 34  Size: 93.0 KB  ID: 110576Click image for larger version.  Name: emblems.jpg  Views: 34  Size: 63.6 KB  ID: 110578

and can say that I won more than I invest in this challenges.

I miss only one wins in this game - to see it fair for dedicated managers.