Yes, preference derives from function...but that is merely part of it. The fact that you prefer the Anakin/Obi-Wan dynamic in the PT to the Luke/Han dynamic in the OT speaks to the incredible amount of subjectivity that we (the individual viewer) brings to the experience. From a writing standpoint, Han and Luke's relationship is more clearly, more efficiently, and (in many cases) more effectively written than the Obi-Wan/Anakin relationship. Again, part of this is because Anakin and Obi-Wan are more central to the overall PT narrative (and have more narrative weight to bear), yet some of this comes down to the fact that (again) we are mostly "told" about Anakin and Obi-Wan's relationship through on the nose dialogue/exposition. Whereas the OT shows us the why/what/how of Luke and Han's relationship. Consider the following exchange: PADME: Annie, are you just going to sit here and let him die?? He's your friend... your mentor... ANAKIN: ...He's like my father, but you heard Master Windu. He gave me strict orders to stay here. This dialogue is used to tell us that Obi-Wan is Anakin's friend, mentor, father figure. Yet, we only really see the mentor dynamic in action in this film. We have no experience with /examples of Obi-Wan and Anakin being particularly friendly with each other and we are 1/2 through the PT. Heck @ThisIsTheWay claims that they aren't even friends at this point, but merely master and apprentice. We have no examples of Anakin and Obi-Wan behaving like father and son either, despite the fact that this analogy is made twice in the movie...though dialogue. If it were not for this dialogue we'd have no inkling that Kenobi and Anakin are like father son because this doesn't come across in the writing, the acting, their portrayals, how the characters behave/interact, etc. Bottom line: You like Anakin/Obi-Wan's dynamic more (find it more interesting) than the dynamic between Han and Luke. That's cool. That doesn't mean that (objectively speaking) their dynamic "functions better" within the structure of the movie/narrative/plot. It simply means you like it better. There is nothing wrong with that. I think these two are my favorite duo as well. However, I also acknowledge that the PT narrative could have done a much better job showing us the development/growth of the Obi-Wan/Anakin relationship rather than jumping from point to point and telling us what they are to each other via dialogue. Again, I think re-writing Episode 1 to have Obi-Wan be the Jedi that discovers/advocates for/bonds with Anakin would have been a stronger choice for the entire saga. Certainly, this is what the OT had hinted at. As I said, I think it's only ROTS that really nailed the execution of showing us the how, what, and why of Anakin and Obi-Wan's relationship.