Unstayed Masts?

[Boracay]

Does anyone know how effective unstayed masts are in practice?
I'm looking at building a 45' steel boat and the initial costing suggests that unstayed masts could be built for arround the same cost as a stayed cutter rig.
The unstayed rig needs fewer sails, fewer and smaller winches, and no rigging.
I have been in touch with a naval architect and he has offered to design the mast(s) for me on top of an existing steel design.
In theory they would save a lot of trouble, though I wonder how easily they could be reefed.
Ideally I'd go for a wishbone ketch with rotating masts.