I had that H3D-II/31 camera before moving to the H4D/40. Here are a few thoughts, most are applicable to any MFD camera use, some are specific to the H:
The general differences between MFD and 35mm ... MFD has shallower DOF at any given f/stop. Higher shutter speed required for any given focal length when hand-held. The aspect ratio of MFD is less wasteful compared to 35mm when producing standard sized prints or page sizes ... so in effect, MFD gains even more resolution in actual use.
The H camera allows you to set a minor mirror delay for hand-held work .... which actually has a visible effect, and is especially useful working with ambient light where slower shutter speeds may be employed.
A tripod or monopod is worth its weight in gold when it comes to MFD work. IMO, many people squander the advantages of MFD with minor camera movement. You can use an L bracket from Really Right Stuff ... which provides access to the sync port on the H camera (some L brackets do not), or use the RRS HD monopod head to swiftly move from Landscape to Portrait orientation.
I suggest exploring options in post processing:
Obviously Phocus will provide the best RAW processing, especially color and DAC corrections.
However, when exporting from Phocus to a finished Tiff file of selects that you want to work on further ... you can use Photoshop Bridge Browser and CS5 ... or you can import into Lightroom-3 as DNGs which I find provides some processing tools that are not found in PS, or are easier to use ... and are non-destructive.
When layers or other unique functions of PS are still required, PS can be directly accessed from LR, used, and the file goes back into the LR library as a version ... as many versions as you want can be done and stored side-by-side in the same LR library.
Output from a LR library is then totally flexible ... the files are there to be revisited for corrections, re-cropping, etc. ... and directly outputted at any size, file format, color space desired without effecting the original.
Use of flash and studio strobes:
The H camera provides the advantage that ALL lenses are central shutters with a top sync speed of 1/800th. To my knowledge, the HC28D, 35, 35-90D, 300 are the only such MFD-AF Leaf shutter lenses currently in existence. All shutter speeds are available when hard-wired to strobes (as long as the flash duration supports it)
However, if you use a radio sender, check what the top sync speed actually is of your unit ... for example, in most cases my Hensel Porty transmitter tops out at 1/250th sync.. My Microsync tops out at 1/350th sync with Leaf Shutter cameras. The Pocket Wizard Transceiver tops out at 1/500th with Leaf Shutter cameras.
According to printed specifications, the Elinchrom Skyport Universal SPEED set sync's up to 1/1000th ... but I've never used one yet to trigger my Profotos in the field ... I will be ordering a set once I investigate it further.
I use Metz speed-lights with the Hasselblad module for general fill. All on-flash controls are bypassed and taken over by the camera, and I've found this to be very convenient because you can do all comp adjustments without taking your eye from the viewfinder ... the H TTL flash meter is very accurate. With speed-lights, 1/800th is available for fill.
I suggest that you log onto the Hasselblad USA site and join. There is a wealth of info and PDFs on most any subject regarding the H system.
-Marc