I don't have the Julia tote either but I have the Patent Leather Charm Tote that has narrow straps...I have not had a problem with the straps digging into my shoulders and when I use that bag, I tend to carry more than my usual load...though I must say I don't carry it for very long distances, i.e. commuting. I love my charm tote (Apple green)I don't have it but worried about that...thus haven't purchased one yet...I do like the simplicity of it and I am a tote girl.
You can;t carry too much in it. I had my iPad in there as extra weight and the strap broke on my cherry one. I exchanged it out for a different bag.