Windows 7 - Non Logitech Track Ball?

I want to get another mouse for my secondary rig, and for the most part, I like the Logitech Cordless TrackMan Wheel mouse that I have on the primary, but there are a few things that leave something to be desired, so I'm wondering if anyone makes any kind of mouse that is similar?

I have been using the same Logitech MARBLE MOUSE trackball with the last 4 computers and don't want to part with it.

I use the Logitech marble mouse on my laptop. More out of deperation because I always have trouble with the touchpad. But on my desktop, I use a keyboard with trackball. That is so much more convenient. The one I linked I got with a $20 rebate that they sometimes post.

I have no intention of parting with the one that i have. I simply wanted to find if there were any options available for another TrackBall for my other computer. Since these are the only replys that I have gotten to this question, I guess that the answer is no. so TrackBalling I shall go.

Is your "other computer" a laptop or desktop?

I use the Microsoft Trackball explorer. I've got 3 of them
Microsoft Trackball Explorer by Office Depot

I should have known that the moment that I ordered something, there would then be a post with another option. No problem though, because I also have a Cordless TrackMan Optical, that has a top ball like that Explorer, and I really disklike it, because I always overcontrol the cursor with it. It took a while for me to get accustomed to my TrackMan Wheel, but it has now become second nature. I can use it better than any other kind of mouse, except for gaming, because my thumb just isn't as fast as a regular old sliding mouse.

Desktop.

Reason I asked is that next time you might want to consider the keyboard with the trackball. That makes only sense for a desktop. But that is even a notch more comfy than the trackball mouse because you can operate it with both hands. The trackball with the right hand thumbkin and the clickers with the left hand thumb. The wheel with the left hand middle finger and then there is another left clicker on the right side for the right hand middle finger. Everything falls right in place and my hand rests on the desk all the time (except when I am typing). I put a soft towel under the keyboard that hangs out on both sides that makes it very pleasant to rest my hands. Somehow ergonomical.

I've been looking at this keyboard from Keysonic which has a trackball on the right and "mouse" buttons on the left.
Has anyone had any experience with this manufacturor?

Scan.co.uk: Keysonic KSK-3200RF - Wireless super mini keyboard with trackball.