I tried every medium format digital back available and then bought a Leaf AFI, which turned out to be a piece of junk.First I had a weird noise issue, which was fixed after the first round trip to Leaf. then it was impossible to shoot with critical focus at f2,8 to f4. my camera went back to leaf three times for calibration, but to no avail. once even a Leaf rep came from brussels to my studio to check my problems. we counter checked with his demo camera only to find out it had the same fault. Finally they acknowleged the problem and took back the camera. this was months after my initial purchase, but as I had leased the back i lost the leasing rates for nearly half a year without having earned anything with this camera. one project only could been saved because I had shot a dozen or so pictures handheld with my Canon. All the stuff I had bought for the camera was sold at a loss, lenses, a Linhof 679, accessories and so on. All in all it had cost me nearly 10.000 €.
I know I had bad luck, but it might seem understandable that I am a tad weary.
My biggest problem with any MF back is the crappy live view. not only is it horrible to look at, it is also badly implemented. With the Canon I start LV and have it on a dedicated 27" screen. The whole team can look at it an work with it and whenever I see a worthy step I hit the trigger and then I get on. Sometimes we have up to five people fumbling with the set, so having a nice big screen is absolutely necessary. No stupid in and out of live view, as it is with Capture 1 and Phocus, no silly T or B mode switch as it is with the MamiyaPhase 645, no daft Aperture closing as it is with any view camera.
When you're shooting food one has to be very quick, sometomes I have only a few minutes or less to get the picture, if I fumble with the camera to long it's back to the kitchen again. Herbs die quickly.
Imagewise I am fine with the Canon, but we're pushing the resolution. I just need more. Another problem is shadow noise. I am nearly always at base iso but I am using hard lights, so recovering shadows is often a bit tricky with the Canon.
Mitchino: I am using flash all the time, mostly only one head, I love fresnels or parabolic umbrellas. My recent acquisition are profoto strip light, magic light for food! then i use a boatload of mirrors to deal with the shadows. this way I have perfect controll over every light spot on my subject. it look very compicated, but is a rather intuitive way of working. Model lights are important, but I am always on fastest possible synch, so only the flashes show.
John: I already had downloaded this, though I am on a mac, but I managed to open it whith Wine. they promise a mac version by the end of 2012.
Simon: what is the fastest flash synch with studio strobes you can use the Nikon with? any Canon I had worked with didn't do more the 1/160 with studio lights.