My paladin hit 20 a few weeks ago and I'm currently planning out my TR so I can tailor my quest-running towards finding gear for the TR. I'm currently still even stuck on the question of THF versus TWF--while I have some nice weapons, this character hasn't even gotten a Greensteel weapon yet (yes, that's on the list of things to get before TRing--I was waiting because of the possibility of switching weapon types on a TR).
I just recently worked through some possible builds, and the biggest question for me ultimately comes down to attack bonus. Because even with all the additional points put into dexterity, my TWF build only loses one strength mod and one skill point per level over my THF build. So the big difference for me is that if I go TWF, my paladin will lose 5 to her attack rolls--1 off the strength mod, and 4 due to dual-wielding khopeshes without OTWF.
So the question...how big of a deal is this going to be? If I go TWF am I going to find myself crippled by an inability to hit enemies in hard/elite/epic endgame content? I know TWF is generally better damage than THF for paladins but if I have difficulty hitting then that's going to be moot.
Although it occurs to me that given the current endgame content, I might be okay with KotC evil outsider bonuses.
Anyway, is attack bonus an issue for TWF? If so, how much of one?