Not a big fan of Cato, but other Koch funded organizations are great. Institute for Humane Studies (IHS), Mercatus Center (GMU econ department, pretty much), Students for Liberty (SFL), etc. Some Koch money went to fund Florida State's (currently where I go) Econ department too, which has Benson and Holcombe - two great Austrian/Public Choice economists.
I can't knock the Koch's much. A lot of the previous animosity between the two groups (Mises Institute and Cato/Koch) had more to do with personality disagreements and egos than difference in ideas, and to be frank, a lot of those personalities are now dead. I'll take good information, research, programs, ideas, etc. when they're presented, regardless of the group offering them up.