I have both but my first choice was the mono. I chose mono because I like the print and I have the PM in mono so I could easily use the PM strap on the Favorite if I wanted to.
However, I ended up loving my Fav MM in mono so much that I decided to get the DE too for the Fall/Winter/bad weather. I like that the DE is carefree (no vachetta) and I wanted a different print (majority of my canvas items is in mono). I'll probably also get the DA eventually to complete the trifecta and use the DA for spring/summer.
I think it honestly just depends on what your preference is, but I do know that the DE has been easier to get online than the mono or DA. If you want the mono, I would highly suggest looking in store or speaking to a SA, that's how I got mine.