For me I prefer the Chanel WOC. I have the medium sized YSL WOC in black with gold hardware just only since December '16 and I've experienced peeling on the corners of my bag already and have used it only a handful of times. I've read in a few posts a few have experienced the same thing. The medium sized YSL does fit more however IMHO the quality on a Chanel woc is to die for. So glad I was able to luck up on one after being put on a wait list. It is my bag I reach for most often since I carry minimal (ysl card holder, lv cles for my keys, lipstick/balm, mirror compact, blotting tissue and fits my iPhone 7 plus)
Also another reason I choose the Chanel woc is because of the strap length of the bag. I'm a crossbody gal and the YSL is too short on me for crossbody and I prefer the thinner chain on the Chanel woc. Overall both bags are absolutely gorgeous. If you chose the YSL I hope you don't experience the peeling / chipping on corners like some of us have :\
Also another reason I choose the Chanel woc is because of the strap length of the bag. I'm a crossbody gal and the YSL is too short on me for crossbody and I prefer the thinner chain on the Chanel woc. Overall both bags are absolutely gorgeous. If you chose the YSL I hope you don't experience the peeling / chipping on corners like some of us have :\