I expressed similar concerns to Magnum about the rack. I've tried a couple of Ortlieb's panniers on my Metro and the design of the rack has them sitting so close to the pedals that I clip them. I have size 11 feet (44 Eur) -- not abnormally large -- and my heels hit any pannier seated forward...
Cheers. I'm looking at this rack for my Metro nonplus but I don't see a seat post adapter in your picture and doubt one would fit the nonstandard vertical post. Did you drill a hole in the ridge at the rear of the post?