A solid baby carrier, though it helps if you are flexible
I got this carrier with Baby 2 after having exclusively (and happily) used a Baby Bjorn with Baby 1. The reason we switched was because while the Bjorn was fine for our petite 10th percentile baby for his entire first year, my back was KILLING ME with our massively huge second kid by month 4. With the belt, I thought it would be way better--and it totally is! The only downside is that it takes longer to get into than the simple Bjorn, and the clip between your shoulderblades takes a little flexibility. But, a minor trade off for not feeling like you need a back-iotomy by the end of the day.