I have no idea which one to buy. I need it for ds1 who weighs about 30lbs and my dd1, although I have no idea what she weighs but she's 2, but a little 2!
I am quite little - 5"3, size 6-8 - so I am not sure I would have the arm length or muscle for the ones at the front although I really would like to hear what is good/bad.