Wanted to share my experience with Logitech Trackman Marble which I bought about a week ago. I got it for around 1000 rs. Was very hesitant before buying it. Did a lot of research on youtube and read a lot of reviews as well. Though most of the people said that it was an excellent trackman, I had never used a trackman before and was quite nervous if I would be comfortable using it. Finally decided to go for it, since I started having a wrist pain with regular optical mouse. To look at it, it is definitely bigger than an original mouse and the trackball is big. The trackball was rough for the first 2 days but I knew it would get smoother as skin oil touches it. Skin oil acts as a lubricant for a trackball. It has been a week now and I cannot imagine going back to my old mouse. I am so addicted to this trackball especially because if its ergonomics, and exceptionally accurate pointer. It has 4 buttons which are completely configurable. Best part is I do not havr to move my hand and thus it saves me of constant wrist pain.(I am into software and use mouse all day long). I can comfortably use trackman on the bed as well, it makes my life a lot easier. Only issue I see going forward it cleaning, since trackman has a trackball(it is completely removable), it would require regular cleaning with a soft cloth in a few months. But the ease and comfort of using this mouse, makes it all worth. Highly recommended product for people who want to try something more than a mouse.
Caution - Getting used to a trackman takes atleast 2-3 days, hence please do not form an opinion unless you have used it well for a week or more. Also make sure you install the CD for mouse and keyboard settings to configure the trackman correctly as per your requirements.