Summary: Bought this for a laptop gaming computer. I have a microsoft trackball with 4 buttons and a wheel on my PC so I wanted to get one that is similar in design as they don't make my model anymore. The Logitech is ok but I really miss the wheel and it is not as ergonomic as my microsoft trackball.
Pros: Track ball is in the center and has 4 buttons.
Cons: Has no wheel, buttons on the right side are not in a comfortable place.
Summary: Give it a proper hardware scrolling option and move buttons 4 and 5 to a better location and I will rebuy the mouse in an instant and give it a 5/5 (improve the firmware to let me simultaneous click and I'll find a way to add a 6th star). It's 2014, these shouldn't be problems.
Pros: -Ergonomic. I have wrist problems and I can just rest my palm on this thing, it's shaped perfect for it.
Cons: -Button 4 and 5 placement... Not ergonomic. You can maybe hit the one with your thumb, uncomfortably, but the other requires some gymnastics. Should be towards the bottom front. Did anyone in Logitech actually ever try clicking those buttons because I'm guessing no. -No scroll wheel. And let me j...
Excerpt: It's a little too long for your hand, and it has a couple more buttons than it needs for your average mouse alternative. I keep having to adjust its position on my desk, but it's still better than the frustrations of a mouse. The roller action is smooth.
Summary:  Logitech - please IMPROVE switches, or offer a "pro" version with a better duty cycle  Logitech - please make a wireless version of this format  Logitech - please make it user repairable if you can't put in better switches
Pros:  Stationary, takes up less space than mouse  Ambidextrous  Comfortable  Short learning curve
Cons: => Switches don't last => Switches don't last => Switches don't last => Switches don't last
Summary: -Logitech Software is, as always, garbage. I have a G500 for gaming, but it uses Logitech gaming software. Marble uses setpoint, which was created for Windows 98 and only upgraded every so often so it can run on a new Windows system, and as thus cannot comprehend multiple input devices.
Pros: Not a thumb-trackball, which I think are massively inferior and harder to control. Ergonomic, comfy, etc.
Cons: -Some people say this mouse is a bit too big, I disagree, I don't think it's big enough, or more precisely, wide enough. -The ball doesn't sit snugly enough in its nest, I can raise it about 3 mm before I have to pop it out of place, and can be easily lifted by accident which deters precision. -O...
Summary: I probably didn't give this product enough time to fully embrace its trackball action. Its no mouse and I didn't feel like trying to reinvent the wheel. If your happy with a standard mouse design.. why change
Pros: -Sturdy -Sexy looking -Good Hand Rest
Cons: -Left button difficult to press -Difficult to control
Pros: Everything already said. I have no doubt I would quickly adjust to using it instead of a standard mouse. Appeared to work as designed, already had the software installed for my existing Logitech MX518 which recognized it no problem.
Cons: I returned it after 10 minutes of use. No scroll wheel. Ok, you can map a button for scrolling. But what isn't mentioned is you don't hold down the button to scroll - you push the button to enable and have to push it again to disable it. This was a deal-breaker. If you do a lot of scrolling (i.e....
Summary: A great mouse for a non-gamer, look elsewhere if you want a mouse that is going to last through numerous clicks.
Pros: Great control and accuracy, once one gets used to the feel of it very hard to go back to a normal mouse.
Cons: The buttons wear out unusually fast. I have used this style of mouse for over 5 years or so and recently I have had to replace them much more rapidly than before. I use them for gaming and probably press the buttons more than an average computer user, but the mouse isn't even lasting 6 months any...
Excerpt: Since I have owned a PC I have used a Logitech TrackMan® Marble Mouse the first one I bought had tiny metal balls instead of the plastic one's they now use. I dont like the plastic at ALL they are not as smooth they dont last as long.