I voted for Rose of May because on principle, if I'm complaining about One Winged Angel, it'd be hypocritical to vote for it Truth be told, it's hard to compare these themes. While I do think One Winged Angel is overrated, I still enjoy it as a boss theme (I'm a big fan of the AV version XD), it's just not my favorite boss theme.
Rose of may, I've grown to enjoy a lot more than I used to I think, especially since Ghost was pointing out how well it fits Beatrix.
Well, I'm not disappointed with One Winged Angel going through; I suppose it deserves it. Still overrated though