RepRapPro was using for all its machines a board equipped with a 32 bit arm processor, the Duet V0.6 then V0.8.5 (same processor as an Arduino Due). A delta printer requires much more calculation power than a cartesian and 8 bit boards are struggling to operate deltas. Typically, you cannot use a LCD screen on a delta with a 8bit processor controller, as it requires too much computing power.
So a 32 bit board is for a delta a major improvement.
The Duet have evolved in a new version, the Duet WiFi and it seems a Duet Ethernet is in preparation
On the Duet, the configuration is also more simple than 8 bit boards, as the parameters are simply defined in a configuration file. All parameters are defined in files which are placed in an SD card. This SD card is also used for printing, which allow the printer to run in full autonomy.
Stepper drivers are on the board and motor current is digitally set by the board itself and can be modified during operation.
A web server is installed on the board and you operate the printer with this web server, through an Ethernet link, or if you don't have a router, through a Wi-Fi bridge. The printer is autonomous so if you loose the link, you cannot see the parameters but this does not stop the print. There is no local panel. A very complete touchscreen panel the PanelDue is sold by David Crocker and Think3DPrint3D. No simple panel is available nor seems forecasted.
Provided your network runs DHCP, the connection to the printer is automatic, simply calling its name (modifiable) in your web browser. Alternatively, you can configure a fixed IP adress. Note that on mobile device, you shall use IP address.
The availability of a very capable web server in the main printer board is unique and makes it the only real 'all in one' board. Others board are using an external computer, frequently a RaspBerry Pi to run the Octoprint Web server.
Having such a capable brain in a low cost machine as the Fisher is unique on the 3D printer market.
It shall be noted that the main developments for the Duet used in the Fisher were not done by RepRapPro nor the board designer, but by independent programmers, the Delta Geometry and automatic calibration by David Crocker (DC42) and the Web server by Christian Hammacher (zombiepantslol).
The Duet had initially scarce documentation but this have evolved with Duet WiFi where you can find relatively exhaustive documentation (sometimes also for older boards) on Duet3D site.
An important information is also the calibration of the Analogic converter, required to improve the accuracy of the temperature measurement. All my calibration shown that the theoretical temperatures were off by more than 10°C (this adds to thermistor inaccuracy).
As for now (oct 2015), the information is only available on this post, however, since this post issue, the temperature G-code have changed and is now M305 instead of M301.
For detailed documentation about the Duet, you shall have a look on the resources of the Duet RepRap page.
For board hole spacing, you shall have a look on the dxf file of the bottom panel of the Fisher (...)
I developed a page on the configuration of the Web interface (a bit obsolete)