Not really, Davies just says that Black loses his castle rights...
Still, I think the Qc1-a3+ manoeuver is quite slow and unconvincing, Be2 is hardly dynamic too.
I'd rather play Bd3 or c4, castle and try to play on the kingside.
Anyway, I don't think this gambit is the best way to meet a +2300 player.
I've recently given a try to the gambit vs the Scandinavian featured in Davies book "Gambiteer I". While it won't certainly refute the Scandinavian, it looks playable.