The Merrill attracts me too. Here is a 36x24 inch print comparison between a D800 and Merrill. If its image detail you want a 5d Mkiii may not match the Merrill. The video features LuLa's contributor Nick Devlin.
First, Barbara thanks for breathing life into this thread. Now, concerning this video: The ergonomics are not nearly as bad as this weird person pretends they are. Regarding the DP2 Merrill Chris Niccolls is wrong. In fact I shot roughly 4000 frames with my DP2M and except the fact that I constantly have to change batteries and the cumbersome raw-->tiff workflow I find the camera to be a joy to use:
1) It powers on reasonably quick. Shutter lag is negligible and while I would prefer the camera to have no buffer, being able to shoot 7 raws in row is fine for almost all situations. When the buffer is full, the camera needs maybe 5 or so seconds to free up buffer space. For almost all situations that's fine.
2) Focus works. I tend to not focus manually because the autofocus is fine. When whatever I want to shoot is tricky, I might refocus and take another shot.
3) The raw workflow is bad, but it's manageable: I download a card to my Mac, power up Sigma's weird software and then batch process the entire folder into tiffs which work fine in Lightroom. On my old mac this takes about 30 seconds per picture, so I'll just let it do its thing and come back one hour later. Sure it's slightly annoying but it seems to be the price you pay for middle format image quality for $1000.
4) The form factor is fine. It's a brick, it's heavier than other small cameras but it's not heavy. You can pretty much hold it all day and it's fine. In fact because it looks so unassuming you can easily take images where a DSLR or a middle format camera would attract unwanted attention. I got away with the "oh, really, sorry just snapping some touristy pictures, haha, bye" routine several times.
5) The image quality IS better than any Nikon or Canon DSLR currently on the market. They are simply worse. Especially when you capture fine structures like, metal fences and in front of some highly patterned walls, or gravel, or pretty much anything that has a lot of geometric detail, the camera is INCREDIBLE. Even extremely fine detail is sharp. In fact at 100%, unsharpened, my DP2M pictures look like scaled down, sharpened images of lesser cameras... You can pretty much print them poster size out of camera.
6) Yes, low light performance is bad. The battery drains very quickly. The buffer should be larger. Sigma's software is annoying. This is all true, but you really need to respect Sigma for accepting these compromises so that they would not
have to compromise on picture quality. Bottom: I simply have never seen sharper pictures and compared to this the quirks are minor and acceptable. As I said before: Buy some extra batteries, batch process the raws, accept the fact that this is not a lowlight camera and everything is peaches and cream.