Hm, sorry to make it look like I was hijacking your thread with pictures of my fish. But I did freak out last month when she started looking 'ragged.' I read all the threads here about fin rot and diseases. But her fins looked healthy. (No black outlines, dead areas or actual rips/tears.) Based on what you've said, it sounds like your little guy is healthy also, and maybe just has the same type of genetics as my girl. Good luck with him!
Post more pictures as he gets older -- I really want to see what he ends up looking like.