I think this is the killer feature for Airbnb. I have loved the idea of the service, but haven't used it because of the slight creepiness worry (perhaps unfounded, but I think common). I know I'd feel comfortable staying with friends-of-friends though. I bet this is a huge draw for many news users for Airbnb.
Speaking from personal experience, you are exactly right.
I used the service a while back just to test it out. I ended up at at place that was technically perfectly fine, but there were a few things that made me cancel and book another place - for a pretty hefty fee.
Again - technically there wasn't anything wrong with it. I haven't submitted a review because I don't know how to do it without being indiscreet.
I'd argue the opposite; I've found it to be very positive to travel and host with AirBnB and CouchSurfing when it comes to, ahem, the opposite sex. Friend-of-a-friend might get awkward, but then again, that's never stopped us either.
I wish there was a way as a renter to specify your place as available to friends-of-friends only. My wife vetoed my putting up our house on AirBNB when we plan to be out of the country precisely because of the (lack of) trust problem.
