A moby would allow you to carry your baby more upright. I suppose being SO close to your body in the summer might get a little warm but you could always dress your baby lightly. I particularly like the Mama Baby slings by Maya Wrap. They are stretchy like a Moby but they are a ring sling. You can wear the ring down instead of up at your shoulder to hold your baby more upright. They're both really cool, IMHO!