I also have purchased the HDS-5.
I am quite happy with the maps, but I really need want to find out how to import/export waypoints. I have updated to the latest version, which advertises "improved import/export functionality", but after going through every menu on the device I can think of, I'm buggered if I can find any import/export function, nor can I find anywhere on the web instructions to do so.
If anyone can point me in the right direction on how to do this it really would be appreciated.