Very positive at the beginning. But after a few months things would always sputter out. No arguments or disagreements -- it would just decline until I threw in the towel. It went that way with INTPs, too. It always seemed like I was the one putting the effort into holding things together, like I was always initiating everything, always doing the pursuing and so on. It wasn't that any of this seemed to be unwelcome, it just seemed like the other person in the relationship was a kind of emotional pillow queen.
Of course, a sample size of a handful of xNTP women is really nothing to draw a conclusion from. Besides, the relationships were doomed anyway: xNTPs leave coffee ground in the sink and don't pick up their damn laundry.