Well I guess Fedex was feeling nicer today and decided to deliver it, so time for my thoughts!
Be forewarned that this is going to be rather stream of conscious writing and not an edited review. Oh, and it'll probably be relatively long...
First thing's first... scroll does work without the drivers! It even has a speaker in it that makes a faint tick to emulate the ratcheting in a scroll wheel for whatever that's worth. But that's where the good news ends. The top buttons are not recognized at all with xev. For whatever god forsaken reason, it appears that they went and made those two buttons into something nonstandard. So until somebody who's more knowledgeable than myself manages to jack on to those signals, you're stuck with a two button trackball with scroll capability in linux... (or in windows if you don't install the drivers)
Meanwhile in windows land, it appears Kensignton didn't want windows users to have too much to gloat about to their linux using breathren, as the driver has a setting count of a staggering 0 options. You're going to use the trackball the way they want you to, and you're going to like it! There's no way to disable a mode and gain another button. There's no separate mouse sensitivity function or scroll acceleration function. It doesn't even appear that the scroll acceleration that windows provides works with it either...
Continuing on the stupidity, the play/pause button in media mode seems to be hard coded to open Windows Media Player if it isn't already. Although the next, previous, stop and volume don't go launching it, so I can at least get
some use out of that mode. View mode is a complete joke since the whole dang thing is proprietary. It doesn't engage on half the apps you'd want it for, and for the ones it does allow the mode to kick in on.. well it might as well not work.
Quite frankly the drivers are absolute garbage. I mean for pete's sake, the help file for the drivers links to their website! Thankfully, however, drivers can be updated, and Kensignton would be stupid to leave them as is... at least if they want to really sell the thing, or have a chance at return customers. They need to make it so the user can disable the mode buttons and reassign them other functions. Meanwhile the modes themselves need to be customizable. It's not the driver's job to decide what application I use to listen to music with! Without those things, the trackball is crippled - plain and simple. While they're at it, they should consider per application settings sensitivity settings, and scroll acceleration, but those aren't as deal breaking as having a 4 button trackball with 1 useless button and another one not having all the functionality it should.
Now that I've ranted about the pitiful software side of things, it's time to comment on the hardware. Thankfully Kensignton's hardware engineers don't appear to be as incompetent as their software counterparts! The design is probably about as good is it gets from an ergonomic standpoint with a trackball that large. The ball hovers a millimeter or two off the desk when it's in the cradle, so the unit is about as low as you can get. There's a positive incline (read: bad), but without physically recessing the unit in the desk, or providing a large elevated wrist rest, that's unavoidable. Should you decide to make your own wrist rest, or if your working surface in low enough that the incline makes things uncomfortable, the unit is quite stable on an incline, so the trackball can easily be forced into a neutral or negative incline situation with an appropriately sized wedge under it.
Dimension wise, rough measurements put the ball at 2-2 1/16 inches high at the peak when in the unit. Meanwhile the silver ring sits at approximately 1 1/4" high, and the base tapers off to 7/8" high at the back and a mere 3/8" high at the front. Width wise, the base flares from 5 1/4" at the user-facing edge to 4 1/4" the tail, and is 6" long.
Buttons are easy enough to click and can be clicked from a large range of locations. They have respectably crisp feedback despite their size. Unfortunately there's a bit of a hollow sound to the rebound - most likely the large surface acting like an drum skin and amplifying the vibration. Only time will tell how they hold up in the long term, but considering they're the only moving parts in the thing, I'd hope that Kensignton didn't cheap out on them.
Finally, the main part, and selling point of the mouse: the ball. The ball comes with something on it that makes makes it rather sticky and prevents it from moving all that well when it's first used. The Kensignton faq states not to wash the ball though, so I left it alone. Sure enough an hour or so later and the thing is moving quite smoothly in the base.
The tracking is capable of detecting the smallest movements that I can reasonably make without purposely bracing my hand where the ball and base meet in order to make micro movements. Comparing to my mouse, it's similar to 800dpi, but anything higher would make the trackball too fidgety to use for any precise movement. At any rate, the tracking seems true to the point where any wandering off course on my back and forth movement is probably my own doing.
Now scrolling... It just works. I wasn't sure how effective and intuitive it would be, but it turns out it's pretty dang good. While in my normal hand position I can place my index finger on top of the ball to create an axis by which to spin on, and then use my middle finger to flick the ball from the side. Alternately I can use both index and middle fingers slightly offset from the top of the ball on opposite sides and then move them in opposite directions. Despite having used my index finger to move the mouse wheel since mice began coming equipped with them, the use of my middle finger to spin the ball feels totally natural. The mouse even locks down on mouse movement while the scroll is in progress, so the cursor wont go flying around when it detects that the spinning motion is the primary motion of the ball. I even tried playing with the ring like it was a scroll ring ala the expert mouse, but spinning the ball is far more natural. You can move the cursor, scroll, and click without ever letting go of the ball.
All things considered, as it stands right now, there's no way I'd recommend this thing to somebody for their only input device. As good as the hardware might be, the crap drivers pose too much of a limitation. A 4 button trackball is already at a functionality disadvantage when compared to the common 5 button mouse. Force the user to use it as a 2 button trackball and you're just letting the competition win.
That said, I plan on keeping it. Since it's an alternate input device for me and not the only one I'll use, I'm not as inconvenienced by it. Then there's the hope that in the future the drivers will not suck... or at least suck less.