Arelith

Keen Senses is phenomenal to the point that races which get it are on par with humans simply because they could be viewed mechanically as humans spending their bonus feat on Keen Senses. While extreme circumstances exist the reality is that your detection investment may as well not exist if you're in combat and lack Keen senses. To this end I'd like to suggest either just making it a feat or making it a 2-tiered feat (to keep the build advantage that races with Keen Senses currently enjoy).