?

I agree that RF may not be the ultimate marker of intelligence, but it is 
the most efficient in our current toolkit.

   If your toolkit contains tools that are inadequate or poorly designed it 
might be wise to recognise this fact and perhaps research toolkits rather 
than seek ETI using the current toolkiit if funding or resources are 
limited.

Plus, the "water hole" is one of the few things we can assume common with 
an intelligence we know absolutetly nothing about...

   Sorry, I don't buy this. While water may seem important to Earth based 
life we have no idea what is important to life elsewhere. The water hole 
seems pretty anthropomorphic to me.
   The whole microwave window might be a better choice but it's pretty 
broad. And it assumes that that intelligence and technology go hand in hand. 
We have little evidence to support this assumption.
   I think that we know very little about life or intelligence. Our 
experience is limited to life and intelligence on Earth at present, a small 
toolkit of uncertain adequacy.

Dave M.