Can those of you that own the Multipli-cite give me the pros and cons of this bag? I think this is going to be my next purchase. I saw a lady carrying one in the store the other day and I really liked it and have been thinking of it since then! Do both straps stay put on your shoulder? so many times with two strap bags, the outside strap slides off my shoulder. Is it stiff or somewhat supple? Thanks so much!