I don't have any trouble to use it, but it might be good to be able to switch between this system and algebraic notation. Also I think you can use this to improve the blind mode.
very interesting! i have to say though that supporting algebraic notation would be a REALLY big deal - i don't really enjoy this feature as it currently is.
i assume that a lot of players think in algebraic notation (i definitely do) and "e4 e5 nf3 nc6" rolls off much more naturally than "e2e4 e7e5 g1f3 b8c6".
winboard implements perfectly my idea of how this feature should work - it supports both "g1f3" and "nf3", and it's not case sensitive, unless the case is relevant. that'd be perfect imo :o
Algebraic notation input would be amazing I think, for the reason Lightsss pointed out (that is why I thought that algebraic notation was how you used this in the first place)