Raspberry Pi vs Laptop - realtime sensor-control feedback loop

What would be the best way to do realtime sensor processing and feedback to an Arduino?

What I have in mind is a robotics project where one set of sensor feedback is processed and then used to control movement based on that feedback. A feedback-control loop.

I was thinking of paring a Raspberry Pi, but if there is a fairly convenient way of connecting to my laptop, and having processing done there, that would reduce the projects complexity a bit.

What designs should I explore?

Looks like communication over serial may be the way to go: http://playground.arduino.cc/Interfacing/Python

But I need to figure out how to get a setup to send back a signal derived from a sensor feedback, to the processor, to modify resulting behavior.

Not familiar with things in depth, pretty much just starting out.

It would be as easy to communicate with a laptop as with a Raspberry PI. This Python demo may be useful.

I think this question is more appropriate for the Interfacing section of the Forum and I will suggest to the Moderator to move it.

...R