i think the most important thing is to follow the baby's clues. if ethan is doing his hungry routine all the time and stuffing his hands in his mouth a lot, etc, it can't hurt to try him on solids and see how he does. it's different for every baby, i'm sure, in so many things. some babies are just hungrier than others.
one thing we noted is to try things on her more than once. s/times, for example, she wouldn't initially like a food. but she would a week later or so. she still does that now. she'll go off s/thing, and then happily take it after a break.