Came across a couple Metris test drive reviews today. All in all they sound quite positive. 24-25 mpg in the mountains of Colorado and I expect test drivers weren't trying to maximize their mileage.
http://www.ccjdigital.com/first-drive-mercedes-benz-mid-size-metris-commercial-van/
http://www.automotive-fleet.com/blog/driving-notes/story/2015/06/mercedes-benz-metris.aspx
(Posting this as thanks to tennispro who posted the ordering information - that was much appreciated as I plan ahead)
http://www.ccjdigital.com/first-drive-mercedes-benz-mid-size-metris-commercial-van/
http://www.automotive-fleet.com/blog/driving-notes/story/2015/06/mercedes-benz-metris.aspx
(Posting this as thanks to tennispro who posted the ordering information - that was much appreciated as I plan ahead)