KensingtonExpert Mouse - Wired Ergonomic TrackBall Mouse for PC, Mac and Windows with Scroll Ring, Ambidextrous Design and Optical Tracking - Grey (64325)

I used a Kensington trackball before but this is another level. Extremely comfortable for my hand given the perfect ergonomic shape, the ball is big but that's also why it's so nice to move, but the best feature is the ring. I love how sensitive it is to small movements. Yes, a bit plastic-y, but after a bit, you get used to it. It moves so smoothly and I can really calibrate how I scroll a page in a very intuitive way. Really great product. I bought the wireless one first (red ball) but then I realised it's battery-operated, so I swapped it with a wired one.

After months of misery using my traditional mouse, I decided to give a trackball a shot. The first two were no good and were sent back (don't go for one where you have to use your thumb to turn the ball), but after procrastinating about it, I decided to try the Kensington Orbit Scroll. To say I am in love with a mouse is an understatement. First off, I can use it with my left hand, which felt a little strange for a few days, but now feels completely normal, giving my right hand a complete break and hopefully some healing time. It is so easy to use - 2 buttons and a ball, plus the scroll wheel which is an absolute game changer for me. If this hadn't been successful, I was going to try the Slim Blade Pro, but quite honestly, I am really happy with this and have no plans to change it for a while.

dropped a star due to the price but it is a good quality item so maybe I'm being a bit harsh. It works exactly as you'd want it to and the scroll wheel is very good. Overall I found all the functions responsive and accurate. It's comfortable to use, well designed and the ergonomics work well. It sits flat on the desk and whilst bigger than a standard mouse it needs less space because it doesn't move around.I've seen some questions on here so I can report that it works perfectly on my Linux Mint 22 system. No setup required. Just plug in the USB and away you go. No extra drivers needed.I don't use it for gaming so I can't comment on that aspect.

I have been using a rollerball mouse for years as moving the traditional mouse around a pad or my finger on a screen is less convenient for me. The bigger ball on this does allow more precision, but it also means that it has a larger footprint.I have been using it for some time now with no problems, so I can attest to its quality and robustness.

super fast - easy to use - ergonomics perfect for me

It's fine. Ish.Only USB B connector, so if you're on a Mac, get ready to hunt out a converter.Very plasticky, especially the buttons which feel worryingly cheap.The track ball itself is so smooth that there is very little feedback as you roll it under the fingertips. Some kind of texturing would make that easier though possibly making things more difficult for the mouse to register.The wrist rest is stunningly hard and feels like it will give you problems if you plan on using the mouse for long sessions.Overall, it's fine, it does its job, but there have to be better quality options (probably more expensive). Only get it on a deep discount.

UPDATE 24 FEB 2011Here is an update to my original review. I just as keen on this excellent input device as I was a year ago when I bought it. It has been in constant use and it really is imho the best input device I have ever used.I use it for graphics, mostly in Adobe Illustrator for example and there is so much control and it is precise. Equally it can go very quickly across screens so I can get across my two screens easily.I also use it for editing video in Final Cut Pro and here, it is really superb. It's great big trackball makes it very easy to just creep forward and back a frame at a time.I really do think that people may overlook this terrific input device because it is not slick and cool, but it is very much the best possible thing for the job.My only comment that could be negative, but isn't, is that using it exclusively may risk RSI problems with you shoulder. I think this is true of any mouse of this sort. That is why I also use the Contour RollerMouse Free. This I use for scrolling around word processing documents and that kind of thing.ORIGINAL REVIEW MARCH 2010I bought mine on 30 January so I've had it for six weeks now. I absolutely love it!I do not use it exclusively, I use it in conjunction with a Contour RollerMouse Free. However I use the Kensington Expert Mouse for graphics. I recently just finished doing a lot of editing of a video with Final Cut Express and the Expert Mouse is superb for this kind of thing.Many years ago I used a Kensington trackball, I think in about 1995, and I really like that one, but this is so much better because it has such a large trackball.The negative things about this trackball are that it feels a bit cheap in construction compared with say, a Logitech or Microsoft mouse at this price, however I think it is well constructed nevertheless.It looks rather 70s to me but I don't mind this. In actual use the feel is very good. The scroll wheel bearing surface is noisy in a plasticy way but there is no problem with this in use.From time to time it is a good idea to remove a build up of gunge on the three little ball bearings. I keep an old toothbrush nearby for this purpose. It's also quite good to take the ball out and polish it, perhaps with your shirt :)Any of these small negatives are hugely outweighed by the fact that the level of control over the cursor is superb. That is what an input device like this is for and that is what it does so well.Before I got this I tried the most expensive Logitech mouse, however the software for that on my Mac was a disaster so I had to send it back. IMHO the Kensington Expert Mouse is a far better buy than that more expensive Logitech mouse. The level of control over the cursor is much better.The software for the Kensington Expert Mouse works very well indeed on my Mac. I use it with the default settings and it is fine. The scroll direction can be switched with a menu in the menu bar at the top of the Mac OS screen and this is very handy.If you buy this you will be initially disappointed when you take it out of the packaging. You will think it is a prop from the Star Wars movie.When you first use it you will think it is a bit weird if you have not used a trackball before. You will still be having doubts.After a week of using it you will never want to use a "normal" mouse again!