I have the zippy mono and love it. I had the pochette wallet last year but ended up returning it because I felt it got too "puffy" when stuffed, if that makes sense. I like the fact that the zippy holds a ton, but stays slim. I use mine everyday (and don't baby it either) and haven't experienced any probs with the zipper tarnishing or changing colors.
I think it's okay to have your accessories matchy-matchy. But of course, it's up to you what makes you happy. I carry the mono zippy wallet, mono mini accessory pochette, mono checkbook cover, and mono poche toilette 19). My "pop" of color is my pomme agenda.