Just thought i'd add that I read about the argument over the DIR-615 being capable of 100Mbit. This may be so but in that case the ports would be maxed out by your broadband connection, there should always be at least a bit of room.. for example if you wanted to do a lan transfer at the same time or if Virgin increase the speed later on.
Gigabit ports should be standard practice now anyway, most computers have gigabit NICs