I’ve been using VMWare for quite a few years now. Version 5 for the last couple. Version 6 came out not long ago with some killer new features (USB 2!) and the academic upgrade was pretty good, so I went for it.
The first thing that threw me is that none of the new features worked in my old VMs. It took me quite a while to figure out that I needed to “upgrade” my VMs, which is under the VM toolbar option. This makes your VM think it has new hardware. It only took a minute to do, but it was annoying that no-one else mentions it. I inferred it from something I found someplace.
Suspend also takes a LOT longer. I never really shut off my VMs, I merely suspend them. They come back quite quickly, and with 5.5 they suspended quite quickly. With version 6 it takes about 90 seconds to suspend, and there are several times during those 90 seconds when all my system resources (of which I have quite a lot) are absorbed, and the machine is unresponsive. That’s disfortunate.
In version 5, if it tried to access something unavailable (cd rom, floppy, sound, whatever), it would tell you, and then stop trying. With 6 it keeps trying, and tells you every time, until you turn off that piece of hardware. Very annoying.
I know I sound like I’m whining, and I don’t like it, but for the most part it works fine. The USB2 was worth the price of admission. Vista support is full now, but it worked fine in 5.5 too, so I don’t feel the joy of the new feature. If you don’t need the new stuff, don’t bother, but it’s nice that it’s there.