Genius has done the impossible with the Traveller 355: brought some innovation back into mouse design.
The traditional central scroll wheel is replaced with an optical sensor that responds to movements of your finger. This sensor is capable of both vertical and horizontal scrolling, and after getting used to the loss of tactile feedback from a mechanical wheel, it becomes second nature to scroll smoothly through pages and documents in four directions.
The laser motion tracking is equally sensitive, offering either 1600 or 800 DPI. You may need to alter the speed settings in to something you're more comfortable using if you find the pointer speeding away across the screen.
There aren't many laser-based mice for notebooks, yet the benefits are a welcome addition for the mobile user, so we expect these to become more popular. Laser-motion works on a wide variety of surfaces, which is handy if you often find yourself working in multiple locations.
The opto-wheel is a useful and overdue design change, making the Traveller 355 a highly desirable alternative to most notebooks' touchpads