I have the 15 Margeaux in brown suede. Haven't carried it yet as I have been spraying it with waterproofing and it's been so warm here, dark brown suede isn't quite right yet.
I did want to mention that the east-west (17 inches?) reminds me of my JPG birkin. I carried it for a couple of years but sold it. I loved the style but the width was difficult to carry as I kept bumping into things when I carried it in stores etc (if that makes any sense). I think the 15 will be good for me as all my birkins are 35s and no problems. I would be cautious about the 17,