Right now I mainly paddle a gus and a burn, but have also paddled a jefe a few times.
The burn and jefe are similar designs in my opinion, except that one is a displacement hull and one is a planing hull. Both of these boats have lots of rocker which allows them to make quick turns and boof more easily (important traits for steep creeking). They are also both very fast creek boats and punch holes well (not as well as the gus of course). I think the jefe might be slightly faster but not by much.
The differences in these boats come from the displacement verses planing hull.
1) The jefe has secondary stability and the burn has primary stability.
2) The burn holds a line way better then the jefe and actually boats pretty well on big water (making it a lot more versatile).
3) the jefe probably feels a little better on low volume creeks, and does really well on the mank.
4) the burn cracks under the seat, the jefe cracks on the chime.
5) Liquid logics customer service is 5000 times better than phyranha's.
6) The jefe's nose acts like a scoop and grabs water and keeps you from going as deep.
7) the burn is way easier to load up for multidays thanks to it's backband and paddles really well with gear in it (I've never paddled a loaded jefe)
8 besides that dis-advantage, the liquidlogic outfitting is sturdier, more comfortable, and better designed.
A lot of it comes down to preference, and which characteristics you like and what your used to paddling.