Full-frame mirrorless
Leica mirrorless system camera doesn't include "compact" in the description.
Size comparsion
Compared to its main competitor, the Sony A7 series, the SL is quite large.
First lens
Although the SL mount is based on the older T mount, the first full-frame-specific lens is the 24-90mm f2.8-4, which is the same size and weight as a dSLR lens.
Big system
Add on the lens hood, and it might as well be a dSLR.
Grip
The grip doesn't have any contouring, which makes it pretty uncomfortable, and the front/top adjustment dial feels like it's set back a little too far for comfort, at least for my hands.
Lenses
The first L-mount lens is the 24-90mm f2.8-4; Leica expects to ship ship two more lenses in 2016.
Viewfinder
The electronic viewfinder is great, with one of the nicest diopter adjustment controls I've seen. It's large with obvious tick marks so that it's easy to reproduce the positioning if it moves. The eyecup is large, and the display is large and bright.
Top controls
The status LCD is high contrast and the Live View (left) and record (right) buttons are relatively easy to feel and press.
Back
The back controls and operation are the same as that of the Leica S medium-format camera.
Buttons
There are four big buttons that bring up menu options with a short press; you can program them to bring up user-selected settings with a long press.
Joystick
You navigate the menus or select autofocus points with the joystick. Its operates smoothly, but it's also too easy to accidentally nudge it.
Connectors
The camera's big enough for full-size USB 3.0 and HDMI connectors. There's also a multipurpose connector for audio and a wired remote release jack.
Dual card slots
The Leica has two SD card slots, though only one supports UHS II cards.
Rounded aperture
As you'd expect from a $4,000-plus lens, the 24-90mm has a nice rounded aperture.
Profile
Though the camera is large, it has a relatively narrow profile.
Other profile
The view from the grip side.