Size, Build and Handling
TL;DR: It's small. This camera really puts the 'compact' in the compact camera form factor. Although I did not compare it with its predecessor, the GRIII shaves a few millimetres off the overall length of the body for a shorter profile more akin to the GR Digital IV camera. Despite the shorter length, the grip is still...well, grippy and comfortable to hold for long periods of time and the shutter button is nice and big as well. Both front and back dials are positioned within easy reach of your fingers, as well as the mode dial and power button. The well thought-out layout certainly makes single-handed use a straightforward affair. Ricoh definitely has the advantage of experience in its iteration of the many generations of GR compacts through the years.
GRIII in hand
The telescoping lens design that retracts into the camera body makes the Ricoh GRIII a pocketable camera. Unlike a Fujifilm x100-style of camera or a Leica Q whose fixed lenses do not retract, you do not need a strap to sling this camera around your body for immediate access when the situation calls for it. Simply slip it into your pocket and pull it out whenever you need it. The almost-instant startup time of the camera definitely helps in this process, as the lens is retracted only when power is off or in power-saving mode. That said, one can also opt to use a wrist-strap for the camera, and the GRIII generously provides you with three strap loops around the body for your preference. As a street camera, I certainly appreciate Ricoh's commitment to making the GRIII as discreet as possible, which definitely puts it above its competition in this regard.
GRIII top view
The startup camera settings is a tad consumer-centric in nature, as the camera by default turns on the autofocus confirmation beep, shutter sound and autofocus-assist light. All these can be switched off, thankfully. You can even turn off the power indication LED light around the power button for a more stealthy profile. I guess it's understandable that Ricoh included the cheesy shutter sound by default because the leaf shutter of the GRIII is incredibly silent. Apart from a soft click and an LCD-screen blackout when the shutter button is pressed, there's no other indication to note when a picture is being taken.
Three user-defined preset modes (U1, U2 and U3) are available on the mode dial for users to program and quickly switch between different settings and modes for various shooting scenarios. For example, one preset could be a highlight-weighted metering mode with auto-ISO enabled for quick-action streets, and another could be set to base ISO to maximise dynamic range for landscapes and architecture shots.
GRIII wide-angle lens attachment mount
The touchscreen is always a much-welcomed feature (at least for me) in modern cameras, and the GRIII sports a sufficiently-sized 3-in touchscreen that recognises standard smartphone gestures like swipes to scrub through photos and double-taps to zoom in on an image. The touchscreen is snappy and responsive, and so is the refresh rate. By default, tapping on the touchscreen in single-point autofocus mode will activate the selected focus point and autofocus only, but users can also opt to fire the shutter through the screen as well by setting that option in the menu. That said, if you are not a fan of touchscreens on cameras, you can turn it off in the settings as well.
Like its predecessors, the GRIII comes with a bayonet-like mount for an optional ultrawide-angle lens adapter, which increases the camera field-of-view to about 21mm. It also includes metal contact pins for the adapter so that EXIF information can be recorded for the lens as well. However, since the 28mm lens of the GRIII is newly-design and thus optically different from its predecessors, the 21mm lens adapter has to be re-engineered as well. At the time of writing, it has yet to be released but should arrive later in the year.