you know, my take is these kinds of things are neat, but there's nothing that compares with the in-depth knowledge and representation of a top-notch, well-qualified real estate person... someone who has your area nailed wrt value, etc.
the real estate guy we used to buy our current home worked with us for 8 years while we pissed and moaned about the places he'd show us... then one day he brought us to this house and in <1 minute, we were decided (she headed off to one area of the property, me to another and independently we decided to buy). he helped us prep, list and sell our previous long-term home and from our point of view - both the sale and purchase transactions could not have possibly gone better.
the point of my rant? like i said earlier - i think these things are nice, but i'll take a local expert any day of the week (and for you old-school types, twice on sunday
hal