I just got back from my Louis Vuitton store and they had 2 of each size and color in stock! I thought I would want the small one, but it was much smaller than I thought. For comparison, I was using my pochette metis today, so I tired to load all of my things in the odeon pm and it was a very tight fit (to the point it made the canvas kinda wonky when I zipped it up) and was not very accessible due to the small opening. Comparing the Pochette metis and the odeon pm side by side, the size looked similar but since the metis is "horizontal", it is easy to grab everything.
I should have taken some pics. I will say when I tried on the odeon pm I loved the look of it, and how comfortable it was. The strap is wide which makes it comfortable as a shouldered or cross body.
But....for me there were too many cons, for the price, so I ended up not buying it.