I noticed Tony Shepperd using one and it looks useful. They are really expensive new but used and tested on Ebay they are around 60 bucks. IDK if it would be programmable with X3 or not. Do you know or have an opinion?
http://www.ebay.com/itm/Kensington-Expert-Mouse-Pro-USB-64213-10-Button-Track-Ball-Good-TESTED-/331365272794?pt=Mice&hash=item4d26e8ccda
 
http://www.amazon.com/Kensington-64213-Expert-Pro-Mouse/dp/B000052WM4/ref=sr_1_62?s=pc&ie=UTF8&qid=1415207318&sr=1-62
 
1k new, 199 refurb, 60 bucks used... That is a HUGE difference. It makes me wonder if I am comparing apples and oranges... or maybe peaches and figs?
 
Then there is the ShuttlePro V2  new for 99 bucks... or would I be better to just stay with a good mouse and keyboard? http://www.bhphotovideo.com/c/product/298670-REG/Contour_SPROV2_ShuttlePRO_v2.html
 
Then, this may be the way to go: The Kensington Expert Mouse Trackball http://www.walmart.com/ip/10778916?wmlspartner=wlpa&selectedSellerId=0&adid=22222222227000026415&wl0=&wl1=g&wl2=c&wl3=40880130032&wl4=&wl5=pla&wl6=78810267272&veh=sem
About the Kensington Expert: http://thestudiofiles.com/?p=778
 
Thanks for the help,
Julien

I recently bought a Logitech trackman and it worked really well.  smooth trackball movement, buttons on side felt right and usable.  was fairly cheap $60-90 bucks.
 
BUT.
 
I missed my scroll wheel so much I went back to a mouse.
 
I am not familiar with any of the models you have listed.  just thought I would throw out there that button placement and scroll wheel may inhibit you and whatever you decide to get make sure you can test it or they have a return policy so if you don't like it your not stuck with it.

The other small Kensington trackball, the Orbit with scroll ring, is actually better and more comfortable to use than that more expensive one, or at least both myself and Mrs tlw reckon so having used both. The only catch is the lack of a middle button. You may find otherwise of course.

The Orbit without scroll ring is huge and feels cheap.

Logitech also make some nice trackballs.

If you want to avoid using a mouse (RSI problems in our case, plus mice use quite a bit of space) you might also consider touchpads which use the Windows 8 touch gestures.

The logitech trackball I have has a scroll wheel (don't recall the model of the top of my head.)  I think it ran about $50 at Best Buy.  I couldn't work without some functionality like that.

I have the Kensington Expert Mouse 4-button Trackball with scroll ring. While the additional buttons might be useful, reaching for them would be a pain if you used them a lot. I love the big trackball in mine. It is wonderful for riding faders: just click-lock and move the ball with one finger.
 
The scroll ring, on the other hand, sucks and I just use the window scrollbars instead. Sometimes I'll simply reach for my mouse scroll wheel if I'm doing a lot of scrolling around. Yes, you can have a mouse and trackball active at the same time, and it is awesome.
 
Regards,
Dan

The model I have with a scroll wheel is an M570.

I have a ShuttlePro V2 which I use on my mac for playing with video and animation.  It's a well built unit and does just what you'd expect from a jog dial, shuttle wheel and a bunch of buttons.

I really like the Expert Mouse (I use the 4 button version at a friends studio) but could never quite justify the cost. I do use their Orbit with scroll wheel track ball, and I like it a lot. I wish it felt a little more solid, but it works well, and if I have to replace it one day then maybe I'll think about the Expert again.

I really can´t use trackballs, but recently i actually found, for the first time, a mouse that is actually useful to use with a DAW:
 
The Nexus SM-5000, you get silent click and scroll and two scroll wheels which can be used for vertical and horizontal scrolls.
Here is my review: http://www.johnkeelaudio.com/nexus-silent-mouse-sm-5000-x-mouse/