If you're looking for a place to stay in Old Town, you've found it. Edgar's studio was excellent; it is spacious, modern, very clean, and couldn't be in a better location. Edgar's flat is only a couple minute walk from the Charles Bridge as well as the Old Town Square, and is within a longer walking distance to Prague Castle. To top it all off, Edgar provided a binder in which he gave some fantastic restaurant and activity recommendations.
This was the first Airbnb stay for me and my girlfriend, and it couldn't have gone any better. Seriously, book it while you can.