mkletch said:Why would the ability gained at 6th level be worse than that gained at 4th? That would be poor design.
I think phase arrow was intended to be used with the imbue arrow ability. Why field an army to lay siege to a castle when an arcane archer could just fire a single phase arrow with cloud kill into the room the king and his court are hold up.
Not to mention an arrow that can negate all natural armor can be a handy trick on those occasions you just can't miss.