Thanks for the kind remarks, Robert. I should point out that I don't believe we should abandon SETI, just that we're going about it all wrong.

We should abandon directed searches of nearby sunlike stars, for the reasons I've pointed out, and concentrate on broadcast transmissions from the galactic plane. Yagis are cheaper to build than parabolic dishes anyway!

Advanced civilizations may be able to harness colossal forces to produce super-powerful signals, but they might not look like the monochromatic, narrowband transmissions we are looking for now. I suspect if we get a SETI transmission it will look a lot more like a natural, unmodulated astrophysical phenomenon than a radio beacon. We will only recognize it as artificial by its uniqueness.

We may be more likely to meet them in an archaelogical setting, we are more likely to find artifacts or other evidence of a long-dead civilization than we are to engage in a dialogue with an existing one.

As for characteristics of the ETI, I suspect that they will be very strange and totally incomprehensible to us, even if they are biologically and physically not too different from terrestrial life-forms. My speculations run to things like the castes of social insects or spacefaring cephalopods. The only thing we'll have in common is that we both use the same technical means of communicating. Sorry, no cutesy, noble aliens for me, I'm thinking something like a cross between a tarantula and a jellyfish, and they are just as likely to be complete and total pacifists as they are xenophobic genocidal killers.

The only thing we can say for sure about them is that they will be totally unexpected, and maybe very, very disappointing.