the loftwing was too generic for me. it needed a name. it wasn't that special of a relationship between the two because link didn't show any backstory or any real connection between him and the crimson loftwing. i really liked epona though. the controls were simple and it was definitely more fun to ride.
I thought it was mostly left alone on part of Nintendo. Near the beginning of the game they made a special point of stating a couple times that there actually was some special connection between the rider and the loftwing. That they could somehow "feel" the presence of each other. But after the search minigame at the start that was never really touched upon or mentioned again. It was stated a couple times that a red loftwing was rare and special, but they never go into any detail as to why it is special. Is it only because that is a rare color? Or is there more to that story? I thought it was a bt lazy not to have some other mention of the loftwings as to why there was some special element to Link's relationship with his loftwing. It seems that after the beginning the subject was just dropped for other storypoints about the world below instead. Nothing else was ever really mentiond concerning loftwings or the uniqueness of Link's loftwing again.
Back to topic, I would have to vote for Epona instead. The loftwings were an interesting addition to the series but the fact that they could only be used in the region above the clouds and never once in the world below does take away a lot of their utility. Meanwhile Epona is useful in most regions of the game and is not limited to a specific region only like a loftwing. Due to the nature of Skyward Sword having a specific tale of people that come from a floating island making them unique from all other villagers of previous games, I do not think the loftwing will be returning for future games. I imagine it will go the way it the King of Red Lions. An interesting addition to be used once then go back to the old standby in later games. Epona might not be able to do any special tricks like fly or swim, but she is versatile enough to be used in most areas of the game without any major weaknesses.