A person wearing an anorak writes....but that's not a DIRECT train service! Admittedly it's not a wholly inconvenient or irregular service, especially if the connections provide enough time to get a cup of tea from the Runaway. But it remains indirect. And if things go pearshaped as they have a...
Seaford doesn't have a REGULAR direct train service to London though. Lewes, on the other hand, has two trains an hour, not per day! Also, train connections to Brighton are very good with the Ashford service running non-stop between Lewes and Brighton.
Personally, I'd recommend Lewes. It has...