I have read that the pathfinder / 3.5 ogl stuff can be kind of a pain to convert over.
Nah, it's extremely easy. Or more precisely, moderately easy if you try to do it "by the book", using the guide from FC's core rulebook for each and every step, and extremely easy if you are more trying to "capture the feel" of the NPC/monster without really paying attention to the numbers. Right now, for a monster without too much weird stuff to it, it takes me about 15 minutes of conversion using the first method, perhaps less than 5 using the second one. I don't think it can get simpler than that, but I do hope it remains just as easy with True20.