Working with this monitor, I get the sense of a company which knows what cameramen need. It's 4:3, so when you use it to frame a 16:9 shot you'll see a letterboxed image. Mine quickly developed a couple of missing pixels; I'm sort of hoping for some more bad pixels so it can qualify for a replacement.
The nicest feature for me is pixel-to-pixel mode (one tap on a programmable function button, and a cropped, larger version of the image occupies the entire 4:3 frame; another tap takes you back to 16:9 full frame). I actually like the fact that the LCD is 4:3 because it makes it obvious whether you're in framing mode (16:9) or focus-checking in pixel-to-pixel mode. There are several other modes I haven't used: some sort of artificial edge enhancement for focus assist, & false color for exposure assistance (haven't used yet either).
imho this monitor occupies a sweet spot in terms of weight, price, and performance. There are a number of different models of the same monitor, for your powering options, video inputs. I think Marshall can modify the monitor after purchase, if your video outputs and powering needs change.