I respect Kaidan. He's down to earth, but he is also a little too trusting in the Alliance, I think. Maybe a little idealistic.
But to answer the OP's question: no, I don't find Kaidan all that interesting. He's like Jacob where neither of them need to be "fixed", and I respect that. But therein lies the "issue": people who don't necessarily like Jacob or Kaidan have no motivation to romance them because both soldiers are vanilla. But for Sheps who don't want any drama in a relationship, Jacob and Kaidan
are good choices; they are strong willed, dependable (if you wish to exclude Horizon for Kaidan), and there is
no drama. But I never got that "head over heels in love" vibe when I romanced Kaidan. Could be bad writing, but I doubt it.
This is just me, though. The kind of man Kaidan is really isn't my type. *shrug*
However, I do really like the conversation he and Shep has about Vernus, and the one following that one saying aliens are jerks and saints like us. It was well written, and that is where I grew to respect Kaidan.