We've hosted a few travelers, either thru WS or Couchsurfing or 'captured' off the highway. Good experiences all. Also been hosted a few times.

One word of advice. If you're contacted by WS email to host, don't just ignore the contact. That is very rude. If you don't want to play host, just make up an excuse and post some sort of reply. 'Not convenient at this time' is good enough.