A good THF is geared as a DD while being semi support. We often pull, and good THFs steal hate with Collaborator often, great THFs can put up similar numbers as heavy DD if given the chance on the right targets (Lower DEF/level/etc) but all of that being said...
You're going to be used as a sac puller and TH whore, that's about it in endgame. We're the only DD class with an A- skill and the lack of a 2H modifier that relies solely on melee damage. (Excluding BST since I'm not even sure what SE wants with BST at this point) our gear is pretty attack starved compared to other DD, and our best abilities (Sneak Attack/ Trick Attack) can be used while subbed for great power and hate control. They won't get the 1 DEX(AGI)= 1 dmg rating, but given their WS, mods, fSTR caps, and damage ratings are superior to start, a perfectly geared THF with Mandau will do as much with SA Mercy that a well geared Hagun SAM with SA/TA Gekko will.
Don't let it discourage you though, SE's been doing some radical changes to jobs lately, so it's very possible THF will be put on even standing with other melee in the coming updates.
THF on HNM attack in Binary. 10010110101