"We hope to find out in our review whether it's an essential upgrade or simply nice to have"
Well, did you? One would hope that after reviewing the product that you could definitively say one way or another.

Here in the hinterworld, after installing on a handful of machines, ranging from old Parallels machines to upgrades from VMware Fusion 2.0.6, we can tell you that it's a nice to have, but not required. Fusion 2+ works fine on snow leopard, albeit slower and less efficiently then Fusion 3.

Fusion 3 looks better, runs a bit faster, uses a little less memory and fewer CPU cycles. Is that worth 50 bucks a pop? Probably, unless you are updating hundreds of boxes, or don't care about such things.

All in all, VMWare continues to produce a quality product, has good support, and provides improvements over time that keep up with the rest of the software rat race. Highly recommended.

Is it still easy to disable Unity and Shared Applications? I'm one of those who DO NOT want the virtual machine's apps and OS so well integrated with Mac OS X. I want to sandbox the virtual machine as much as possible.

Thanks in advance.

Performance is terrible for V3, constantly accessing the hard drive even without a VM running. When a VM is running, my CPU temp increases at least 20 degrees. These are unacceptable issues that did not occur with V1 or V2.

Have uninstalled V3 and reinstalled 2.06

Try VirtualBox. It works great and it's free.

http://www.virtualbox.org/

It's only free for personal use.

Although this is the Mac. I guess it isn't ever used for business...