I'd say kat-a-LEEN. Never would've thought to pronounce that like
Caitlin.
I like
Caitlin. The name itself with all spellings counted is quite common, although I've never heard of one much younger than me (mid-20s). I think most Caitlins I know spell it
Caitlyn. I know a few Kaitlyns too.
Caitlin I don't think is the most common spelling, at least in my experience, and it's by far my favorite. So I think that makes it even more usable.