Agreed. I have that love-hate relationship with the NF titles and not surprisingly, I can't convince people who don't know me and the system well that I'm really am an Fi dominant. It was weird for me to accept too because being an NT was so ingrained as a self-image and I come off as a stereotype NT. I just don't think like one in the sense that my T function is ego-conscious although I obviously rely a lot on my T function when I reason, probably more so than F for most of the part. So I mean, by that logic I could equally type as an ENTJ lmao, except that I'm not ordered and such like J types are supposed to be in the MBTI system.
I have no problem seeing you as Fi dominant, or even a MBTI INFP. I actually had more trouble seeing you as Ti dominant. The saga of trying to type my brother taught me a lot about Fi. It's not going to look like stereotypical "F". In fact, to the more novice eye, it can look like T. I would have sworn my brother was a T. He kept on testing as ISTJ, which I knew wasn't him, because my sister is ISTJ, and they're very different. But he is very logical and intellectual, and I could see the Te, but he's clearly N, so I went with INTJ. (What was funny about that...I often thought, wow, his Fi is really strong. d'oh!) But. In hindsight, the Te I was detecting is definitely inferior...the hyper-criticism and his neuroses surrounding Te matters doesn't lie, but at the time, I was too novice to see it. I gave him a cognitive functions test, and it blew my mind when the top three results all came back F preferred. That's when it all clicked for me, and I had to completely reevaluate everything I knew about Fi. Part of the problem is that he's an NF, the only boy, with an ST father, two ST sisters, two ST best friends. My brother and I get along the best, because of my secondary preference for NT. He buries the less "manly" aspects of Fi. Like, now that he's a confirmed INFP, he has admitted to me that while I try to make decisions from my intellect, he makes decisions and operates out of his "emotions" first. Mind blown again, mostly because I couldn't imagine living like that.
My point: Fi can look like a T preference at first glance. My brother is also a 6, so he does have that head center energy that fuels his intellectualism. The fact that you're also a 5 adds to this illusion of thinking preference even more.
Yeah, so the question becomes if your dad is an INTP because functionally it lines up better or whether he's an ISTP because his two ego-conscious functions are Ti and S. Ultimately do you feel that you two are that much different in terms of thinking?
In his case, I still call him ISTP because his two ego-conscious functions are Ti > S. He really doesn't fit into the INTP/NT persona. For myself, I call myself ISTP, because functionally I'm ISTP, and in my case, I can't tell if the Se or Ni is more conscious. And I know I have a slight preference in favor of sensation.
As I've been getting older, my thought processes have diverged more from his, but we still think in similar ways. I would say he's more pragmatic than I am. Not to say I am not practical...I am very practical. But not to exclusion of the intellectual, and vice versa. My father though, he is only concerned with pragmatic matters of life: work, saving money, the concrete realities of life. And this is not a bad thing. These are his strengths, and he excels at them. He is the one who taught the meaning of a strong work ethic and the worth of a dollar. Very street smart. However, the downside is that his pragmatism has trouble seeing anything he doesn't understand as valuable. If he can't see the pragmatic use of it, it has no use. He is all function over form. My mother on the other hand is all form over function, and not very practical at all, God bless her. So I was exposed to both schools of thought, and that has informed my differences in thinking from my dad. I have an appreciation for both form and function.
Like, my father doesn't understand the world of higher education. He got his diploma and went straight to work. He did encourage my siblings and me to go to college, but that is a practical reality for getting a job in this economy. But he still doesn't understand it. I know he's proud of me, but when he doesn't understand something, he subconsciously devalues it at the same time. For instance, he has had a hard time understanding why I'm applying for internships, and why I don't just go out and get a "real" job. Not even exaggerating here. It took my brother brow-beating him with the fact that internships are now an essential step to getting a foot into the work world and using my very-successful sister as an example for my dad to even acknowledge the validity of it. She had an internship before getting her very well-paying job. I'm extremely proud of her, but her success straight out of college has made it more difficult for my brother and me with my father, especially since we're not going into a business related field like she did. It was smart of her. One, business suits her far better than it does me, but two, business is something that my father understands.
Another difference between my dad and me, he's a 8 and I'm a 5. This area does not cause contention at all. Despite our differences, we've always shared a close connection from the time I was very young. Everyone calls me the favorite, which is true (except for my dad, who refuses to acknowledge that he has favorites). I've always been independent and strong-willed, albeit quiet and reserved. I think he saw and sees something in me that reminded him of himself. We both don't take anybody's crap. I actually understand what is going through his head, something that my sister and brother haven't mastered and have given up on.
Calm down there, [MENTION=16405]LeaT[/MENTION]! What do you have against bards?
The NF titles are very bad too. I feel like the S ones are just bad all around, but the NF ones have two effects...people want to embody whatever trait the title is implying, when they might not truly be NF, or it repels people who actually may be that type, but don't identify with the saccharine descriptors. My brother would be one of those INFPs. I thought he was an INTJ when I first got into type, because I could not see him in the cookie-cutter INFP descriptions. 
