I’ve had a trackball even longer than I’ve had a tablet. My first one was a gigantic thing with a ball the size of a billiard ball (in fact I used an 8-ball as the main ball in it for years). They actually still sell it too 
I’ve had a one in one form or another since then, as I love them for FPS gaming…the old version of the marble was such that you could fling the marble really fast…too fast for the driver to handle. So it would interpret a huge fling forward as a quick back step, then a run forward…or a step left, then quick right. Killer Now I just use it for aiming. Awesome in Bioshock. But I digress.
More after the jump.
The Logitech cordless TracMan Wheel trackball itself has three buttons and a wheel, like most mice do these days.
The wheel has the “gear” feeling to it, which I like. The jump range can be adjusted in software. This is the wireless version, and a wired version is also available for a few bucks less. It takes one AA battery. The receiver part is one of those old-school things that looks like half-a-mouse attached to a USB cable. Fine as far as that goes.
The Good
I have a large hand…it goes with the rest of my large 6′-7″ body. And because of this, I long ago gave up trying to find a mouse that actually fits my hand. But this comes the closest. It has a comfortable curve and since it’s stationary, I cut a piece of an old mouse pad to sit under it, raising it even more. So comfort-wise, this one is the winner for sure.
I find moving the wheel with the thumb quite easy: the ball itself moves very easily, as the tracking is done optically (as opposed to rollers like the old-school tracballs used to use). Not much to say about this guy really, just a great tool.
The bad
There are two drawbacks to using this thing. The first is that, until you get used to it, your thumb will ache if you use it for an hour or two. Eventually this won’t happen as you get used to it, but in the beginning…ow!
The second drawback is more long term. I have been using a trackball from Logitech for at least 12 years, sometimes as the only pointing device attached to the computer. Now, remember, my hand is huge, so even with the extra padding to make it higher, my hand is still too big for the trackball, and the “heel” of my hand rests on the table. Specifically, the outside of the heel of my hand. At this spot, there is a bone, and most of the weight of my hand and arm rests on this spot. (If you’re curious, look at your right hand, palm up. At your wrist, you’ll find a little bone sticking out on the left side. That’s what I’m talking about). When I first started using a trackball, this spot got very sore, so it’s worth knowing that you’ll need a pack of band-aids to go with the trackball for the first little while.
I found the wireless range for this thing to be normal, unless I put it on my Wacom tablet…then the range goes in the toilet, like to under 2 feet. Must be some kind of interference between the two.
Finally, as with any new pointing device, it will take some getting used to. And you just may not like it.
Conclusion
I like trackballs. And I sometimes use this one for everyday use. But not often anymore…I prefer a normal mouse these days. But as with the Wacom tablet, it has its niche: for me, that’s any type of FPS game…almost any game actually. It makes aiming really quick when in free-look mode. If it had more buttons, it would be even better!
…Mike