I prefer Mini Pochette (I have 3), Pochette Accessoires (2) and Eva (1) and never gave Milla a second thought. IMO she is too flat and too expensive for what she is. But as always, this is just personal preference. Good luck and have fun deciding!
I have 2 millas (mono and da)...no pochettes. I like/prefer the hardware and the alacantra lining on/in the Milla....but it is flatter. I guess it would depend on what purpose it will serve for you. I use an Eva strap when I want the Milla crossbody which I bought extra for that purpose, and to use with my Favorite mm.
Edit * forget to add I also bought the vachetta wrist thingy to also use with it (thinks it's called dragonne).
I have both and for a grab and go type of bag I reach for the mini pochette.
I would say the Milla and mini hold the same amount, it's just the Milla is very flat so I use it when I'm going out to dinner with friends. I mostly use it as a shoulder bag but for a wristlet I prefer the mini.
how about a "what fits in my milla" thread? I have the milla in DA and I am always shifting items to get them to fit. I love this little bag but it terrorizes me to use it as I am a "stuff any and everything my huge oversized bag and go" type. I also have the mini Pochette in de and I seem to be able to fit a little more inside. oh the struggle...