3d Mouse???

This device won't make your work better. It's supposed to make it more comfortable when you work and that's very subjective thing and everyone has different tastes. I've been doing 3D graphics for almost 20 years and I'm pretty much used to standard mouse and keyboard. I had this Space Navigator in a company where I worked once and I had a lot of time to try it and use it but I never got used to it and it just ended in a drawer under the table and I still worked with my mouse. So you better try it and see if it helps you or not but don't expect that you'll be able to something new or better that you can't do now. At best it could help you with the comfort when navigating the viewports and such stuff but maybe not even that. I know many people who have similar experience like me who tried it, saw no advantage and sold it again. But also many people use it daily and they got used to it so it's kinda 50/50 chance that it would be useful for you :)

I've just purchased this item :)

I work with a space navigator for 4 jeers now and I can't imagine doing it any other way. My first experience with it was bad only to discover that it was my failure to set it up properly. Symptoms of bad setup are for instance movements with the device translate counterintuitive to scene movements, ore movement in some directions are too sensitive etc.

The device has many settings and you should take the time to make yourself familiar with them very well, if you manage to setup the device properly then you will fly around your scene like a bee (with great ease) in no time.

I highly recommend working with it as it makes your mouse completely free and independent from navigating your scene.

The thing works very well in 3ds max, don't know how it performs in other packages. Work's also relatively good in 3d coat and it is also nice to use with Google Earth. I've experienced some problems with it in Mudbox, integration seems to be flawed in there. Sadly there is no support for it in Zbrush.