keep in mind that the public defender, while very good at maintaining blade stability under extremely abusive situations, will not slice through heavy material as well as the thinner blades.
by thinner i dont necessarily mean thinner then 3/16" thick, i mean in overal geometry. the pub defender has a ton of steel right behind the edge, and it gets to 3/16" thick pretty fast. its the same thing for all of the pure bred fighters.
if you intend to do a lot of heavy stabbing they're good, though i'm pretty sure the pub defender would have a hard time with stabbing heavy or thick materials as well (leather specifically).
but, if sharpened to 20 degree's per side or lower, they start to be as proficient at initiateing a cut as anything else. if your willing to grind for a few days with a sharpening stone and take the pub defender down to 10 degree's per side it would be excellent. however, if you intend to do that your going to end up completely overtaking the forward grind on the tanto. (meaning your sharpened bevel will be from the cutting edge all the way to the the 3/16" thick spine, puuko style)
that and i dont really like the 3rd gen style handles.... a lot of people love them, i just always felt that the index groove was to deep and left the blade feeling like it was slipping back in in the hand all the time. ymmv.
pesonally, i cant think of any busse i've handled thats better then my cut down thin NICK. i'm hoping the customs i have on order will be even better. it doesnt have a choil to snag on, i its just at that length where you start to lose indexing ability with the tip (so i can pick it up and know where the edge is, but if i need to make really delicate cuts blind, i have to put the side of the tip on the item first, or choke up and grip the blade itself).
if i had to chose a stock busse, i'd personally go with the standard satin jack tac. the blade is long enough that you dont have to worry to much about the choil (though i still do (i hate choils if you havent noticed)), and the handle is very secure. its contoured differently enough on both sides that you can index what orientation the blade is blind. its 3/16" thick, but it has a nice balance of geometry thickness.
its stuck between the two worlds for me, thick prybar and thin slicer, so i've never had any desire to actually carry it, but every time i pick it up it feels better then any other knife i've held.
also, the comments above are about a "fighting" knife - wich by my definition means a knife that is meant to be used in hand to hand combat, meant to injure the human body.
if you mean a combat knife, as in something that will be used in the feild of war - wich by my definition means a heavy general use/abuse, then the comments do not necessarily apply. for a combat blade i'd still pick the standard satin jack tac
for a combat knife, i also really liked papa thuds comments on the badger attack-e, having an extremely secure handle that will never slip from your hand (as long as you can actually grip it).