Slicing manually?

Is there anyone out there that slices their 3D designs manually to try and see how the printers respond? It seems like all the slicers out there seem to do the same thing. It simply slices in equal layers. I imagine there are ways to print stuff that would turn out better if you were to utilize the Z-axis as a printing axis rather than just to move to the next layer. Has anyone tried this at all? I'd love to see some results.

Take a look at this thread on Topolabs - they're doing some interesting things with top layers along the lines of what I think you're getting at.