I believe if humans had to chose which way to make decisions, it would be better to base them purely on rational thought. I think emotions can really skew a persons perspective and possibly send them down the wrong path. Rational thought would help take all considerations into account before making a decision, which is a little bit more rounded approach.
Yes, humans should use rationality in making decisions. However, humans are emotional beings and they should take their emotions into account when make decisions as well. A good balance of both would make for better decision making in the end. Emotions are sometimes brought on by intuitions that may prove to be right so they should not be completely ignored.
Really, decisions could possibly be a combination of both rational or logical thought and emotions. That being said, acting on emotions only can cause us to do rash things without fully thinking through the consequences. Because of that, it's important to use logic to think through the pros and cons of a situation before making a decision.
We would not be humans if we made decisions strictly on rationale.Although this might be ideal it's a rare human that can put their emotion totally aside and exist strictly on rational thought.This almost takes the humanity out of us and it would not really worth living if we could not call ourselves human.
The best decisions are made with a combination of both. One should do one's groundwork by checking the facts and looking objectively at various outcomes, But then one has to go deeper into emotions or maybe it is better called intuition to make an informed decision that will be good for a long time.