I had considered the Propeller, and the issue is that memory accesses are *slow* on these, and each cog has a specific amount of memory its allowed to access. And the total amount of memory available per cog is slow.

I know about arduinos, I built a robot based on a arduino, and I have a arduino in my toolbox. The parallax, being a multi-core processor, is designed from the ground up to be useful for parallel programming. I reallly wouldn't be taking full advantage of the multiple cores, because everything is completely sequential. LocalTalk packet recieved from serial->tear it apart->convert it to a ethernet packet->send out. and the reverse.

If I did this with a prop, I could certainly have two or three cogs work on multiple serial packets (or ethernet packets coming from ethernet) it's not completely thread-safe, IE I could have a situation where packets could "process" in the wrong order and cause problems.

Those are the reasons why I was leaning toward arduino. I think the propeller is neat ( and I do have a project that will totally take advantage of its unique and awesome power) but I'm not sure if it would be useful for this..