I like that it's easy to navigate through their website when looking up domains you're interested in purchasing or selling.
It takes some time getting used to navigating around but once your familiar with how things work there isn't anything really wrong about using this service as long as they are still active! If someone has an expired registration of a popular keyword then its very difficult if not impossible to find another seller who will sell them at fair market value. This makes finding good sellers much harder than it should be so we have had many issues trying to get our keywords sold by other companies due to expiration dates etc.