Apart from the initial cost/refund thing, is the only difference between the regular Oyster card and the Visitor one the inability to load a weekly travelcard onto the visitor version?
Also, what's up with the peak vs non-peak when checking out fares. I'm using the official single fare finder site and depending on the route I get:
- peak up to 9:30 and between 16:00-19:00
- peak only up to 9:30
- no peak times