wilbur wrote:
I've been doing a lot of learning about hand planes recently, and was
interested to see the differences between metal bodied and wooden
planes.

Then I read about infill planes. They look really nice, but can anyone
tell me if there is a functional advantage of having the wooden infil
vs. a regular metal bodied plane?

It's how it's made that's the major advantage. Infills start out as
flat plates and are machined prior to assembly, as opposed to starting
out as a casting. Castings shrink as they cool and it can be a fair
amount of work to get the sole dead flat. Infills start out that way.
The weight is another advantage. There's also more hand work involved
in making an infill, so each one is closer to a custom creation.

R