If you use taper edge boards then only the band either side of the joins needs filling. Many decorators then paper direct onto the plasterboard which makes for a quick and easy job, until the time comes to strip the paper (it is almost impossible).
If the new boards are given a skim coat then there is a hard surface which makes decorating in the future much easier especially if wallpaper has been applied.
They both have there positive and negative points, it's an alternative option. Both can be papered, painted, tiled.
Joint filling although dustier overall job, will allow you to work on top at an earlier stage than plastering.