When I try to transfer a .py file to my phone (ignoring py2sis for now) I can't see E:\System in PC Suite's transfer application.

Obviously I could upload it to E:\ and then move it using FExplorer, but that's hardly streamlined development

How does everyone else transfer .py files?

I know Python isn't the main app source for S60 devices, but I assume someone's got a reasonably smooth setup (edit script in your choice of editor, single drop target to drag from WIndows explorer to the right place in the phone, running Python on the phone choose Run script, bingo bango).