If I didn't have an S-6 I would get that first assuming you're looking for a great "do everything" knife. The size, the blade width and length, the grind, just everything is "right", for an all rounder.

If you want a knife to use often as a chopper with some general all-around use thrown in then the Mojo might be the better choice. Plus the recurve looks cool <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

Realize that I've never touched a SYKCO Guard/Hook at this point so this is a recommendation biased by my having more experience with the S-6 than the Hook.

At the end of the day, either knife will serve you well.