I managed to convert my existing Virtualbox VM disks to VMware formats using Win-Image and it does seem pretty swift.
I much prefer the ability to be able to drag and drop between VMs or between the VM and host.
The only slight niggle I have, and its more to do with the way I run the VMs on a daily basis, is that you cant have one VM full screen on one monitor, and another VM running at the same time windowed on a second monitor.
I have a VM image of my work laptop (as it runs better on my i7 than it does on my laptop!) running full screen on one monitor. I then have another VM running in a smaller window on the second monitor for VPN'ing into customer networks.
Virtualbox handles this fine, but VMplayer either windows both VMs or full screens both VMs.
Still, I think its a small price to pay for drag and drop and better USB support. Also clipboard sharing between all the machine seems a bit more stable and reliable too.