Reason will work with relatively modest computer systems, but more CPU power and more RAM translates into more modules for your rack. Using ReWire also ups the power ante, because even though ReWire is pretty much just a passive conduit, running multiple programs by definition requires a more powerful computer. The Modules Let's look at the modules in a bit more detail. Note that with large rack setups, you could go nuts just scrolling from one end to the other. The sequencer is also permanently installed.
Reason connects up each new device in a normalized, logical way.
You can name devices and move them around. The various devices have modulation inputs and outputs, allowing control of, say, a Subtractor filter input from an NN19 audio output. You can go really crazy here. And of course, unlike the modular behemoths of old, patches get saved with the song. If you run out of inputs, create more mixers.