I'm thinking most people don't use the original satoshi client
Although lightweight clients look nicer, I'd prefer to run the satoshi client to support the network. Others should do the same
How does that support the network?
If you're using lightweight clients like Multibit you're just backpacking off the people using the satoshi client. Running a full node helps protect the network.
If you run QT you have a node is that correct?
That's my understanding... but I don't consider the number of nodes a crucial result
That is why I use it. Even if it helps a little I am happy to do it.