Personally I have grown to love Arrius..the dry pond area especially. Each different side of that keep has alot of interesting rocks and trees and places to hide etc.The mine has behind it a passage that is great for ambushes etc.
I don't really care for BRK..all that sulfur is just ugly..and its near sejanus and I hate the bridge to sejanus..a lot of dieing there and the slaughterfish in the rivers..that keep is brutal.(and outposts I don't really care for either...they turn too quickly)