When comparing Razer Imperator vs Kensington Expert Mouse, the Slant community recommends Kensington Expert Mouse for most people. In the question“What is the best gaming mouse?” Kensington Expert Mouse is ranked 55th while Razer Imperator is ranked 96th. The most important reason people chose Kensington Expert Mouse is:
With thumb and pinky on the buttons and three fingers controlling the ball, the user's wrist lays flat on the table (or on the provided attachable wrist rest).
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Dual sensors (laser & optical)
The Razer Imperator offers a dual sensor for optimal sensing on any surface.
Pro Adjustable side buttons
Users can adjust the position of mouse buttons 4 and 5 to better fit their thumb placement.

Pro Comfortable and ergonomic
With thumb and pinky on the buttons and three fingers controlling the ball, the user's wrist lays flat on the table (or on the provided attachable wrist rest).

Pro Intuitive link between ball motion and FPS camera angle
The ball is large enough for turning it to feel like physically rotating an object.
Cons
Con Suffers from double click issue
After a bit of use the mouse might start experiencing a double click issue with its buttons.
Con Not a mouse
This is a trackball, not a mouse.

Con Questionable secondary button defaults
The upper left button, which is the hardest to use, is middle click by default. The upper right, which the ring finger naturally rests near, defaults to Back. This can be particularly annoying as the Back button is easy to brush when moving hands between keyboard and mouse.
