I fly about 26 RT's per year, sun through friday. I almost always check the bag.
a) Even though my travelpro is a rollaboard, it's still a hassle to carry around with me & thru security.
b) I don't mind spending a few minutes waiting for my luggage--I bring a book
c) I carry my laptop with me, so a lost luggage situation, while all-too-frequent, isn't a catastrophe (although it is a little smelly).