Thanks, I've decided to go the RhinoCAM route. One because I use Rhino, but another is that the machine is 6 axis, and Rhino CAM will work with 6 axis indexed.
I should stress though, the rough cut problem I was having was NOT due to MeshCAM, it was mainly due to the part not being held down stiffly enough and clamping in a way that my bit wouldn't eat into its supports. MeshCAM works fairly well. There are a few issues, like pocketing. I didn't like how it did that, and it had a lot of unnecessary plunges, but other than that, it's well worth the cash.
Barry