SmartView Duo or HD?

I just got my ATEM TV Studio and realized that the cheap $100 monitor I was going to use w/ multiview isn't gonna work. My goal is a small mobile rack case for mobile streaming to uStream. I have enough funds for a SmartView Duo or a 17" HD, but not both. (Well maybe both one day, but not in the next few months.) I'm thinking I should go w/ the HD since it will show everything in multiview, but I'd like to get some experienced users' opinions. I see an example on here of a mobile rack system that uses 2 Duos (also a control surface setup w/ the same)-- which makes me think that for some reason it might be better to have the small preview/program independent views. Having never done this (except with Wirecast) I don't wanna make a $800 mistake. Any advice?

(My setup is/will be all HDMI-- 3 identical cheap Sony HDMI cameras running at 720p or 1080i. (I might add more cams in the future.) Internet streaming via MxLite (until BM offers a Mac solution.))