You are analyzing this way too much. People have given you sufficient advice to reach a decision.
Care about your paper most? Present where your paper counts.
Care about your job prospects most (which is the one I'd choose)? Present where job opportunities are most fruitful.
Care about awards most? Go to the conference where are you are most competitive for the award.
and on and on ..
But how do I know which one I should care about most? :/
If you're single, go to the one where you can hook up with scholars with jobs in fields more employable and lucrative than yours.
BPN's suggestion is brilliant! Blow off both conferences and go to an engineering conference. Look for the most decisive person whom you find attractive.
If you find yourself overwhelmed, come back here and post pictures and we'll help you decide.
