I would definitely say Adrift is probably my best map. The layout and narrow hallway action suits my mid-range style. Haven is played so much I am not bad at that either.
I absolutely get murdered on Abandoned. I don't know what is wrong with the map, it is just so weird. It is so easy to be picked off in some areas by everyone because of the openness, and the areas where if isn't open are normally congested with battle from scattershot/shotgun/boltshoters. I just cannot get a good game on this map if I am playing Regicide, and team slayer is hit or miss depending if you are not playing with a group of schmucks.