Mate, what controller and setup did you use for the MillI've converted two mills to CNC, a micro mill (Sherline) and a 1 HP Grizzly G0704 mill.
I have to agree with the idea that learning to make some parts by hand is a good way to start. One reason is that it forces you to think of making straight cuts in X and Y - and coming up with ways to hold the part in a fixture. Holding the parts is critically important. Say you need to cut a part with a tapered side - with CNC you just tell it the start and stop points and it figures how to do it. With manual milling, you need to figure out how to do it in a straight X or Y cut.
The tradeoff is that if you're going to do a lot of parts manually, manual mills are much easier to use with Digital Read Outs - DROs - I get distracted very easily while counting rotations of the cranks. A good set of DROs will cost close to what it costs to convert to CNC.