Cameras with longer battery life can take more photos before exhausting their batteries.
Special note: The measurement standard for battery life stipulates that if a camera has an internal flash, it must be used for 50% of photos taken. For this reason, comparisons of one camera with an internal flash to another without will not be comparable
The first genuinely compact--almost pocket-friendly--compact system camera, paired with equally small, interchangeable lenses. Great ergonomics for the size, and it feels like a real camera, not a computer with a lens.
Very restrictive lens selection at launch. All but two current lenses have severe limitations in functionality. Performance is sluggish, and image quality trails large-sensor cameras by some distance.