You only need the Debug Brick if you want to debug the low level C firmware of Bricks or Bricklets. It does not add any features for PC based programming.
In hardware version 1.2 the D-Sub 9 connector got replaced with a Mini-USB connector and a Silicon Labs CP2104 USB-to-serial converter. This converter requires an extra driver that can be downloaded from the Silicon Labs website.
|Dimensions (W x D x H)||40 x 40 x 8mm (1.57 x 1.57 x 0.31")|
The (now obsolete) Debug Brick Hardware Version 1.1 has a design flaw. GND pins of the JTAG connector are not connected. This can lead to debug problems when using the JTAG interface. The serial console is not affected. The problem can be fixed by soldering a wire from a GND pin of the JTAG connector to a GND pad on the board. This issue will be fixed with the next hardware version.