Here is our video explaining the differences: https://www.youtube.com/watch?v=tKBxXck2B3k

The tactical frame is our most robust frame and is recommend for awkward loads such as tree stand, barrels, etc. because it will resist flexing around these weird shapes. This is also the preferred frame for military use. 

https://kifaru.net/store/frames/duplex-tactical-frame-newplex-ss/

The Lite frame is a skeletonized version of the tactical that will carry as much weight as you're willing to but be just as comfortable. There is about a 1lbs difference between the current Tactical Frame and the Lite. The Lite is recommended for just about everything such as packing out meat, carrying gear, backpacking, etc. It’s the same thickness as the tactical but lighter and breathes better.

https://kifaru.net/store/frames/duplex-lite-frames-hunting-hauler/