Well the question is not specific to IQ intelligence or Social Intelligence. In regards to success I believe social intelligence or social IQ is more important. Lets say a person is very knowledgeable about different topics but that same person does not how to treat others or lacks the skill on how to get people to like you and accept you. If an intelligent person lacks social IQ, it would probably have a hard time advancing in life.
Even insurance companies have more expensive policies for doctors that are not likable, since these doctors are more likely to get sued for malpractice. I once knew a patient that was the recipient of a bad surgery, she refused to sue her doctor because she liked him so much.
There are countless examples of intelligent people that are very much disliked by others, simply because they lack the skills on how to relate to others, how to be friendly, how to be outgoing etc. Often times you may have come across a wonderful person, however you may never know it because that person unknowingly never gave you the opportunity to get to know them.
Another important skill i noticed on intelligent people is the ability to fail and fail again and always have the ability to move forward with the willingness to yet fail again. Some folks are just terrified of failure, not realizing that failure is just a door to eventual success. Failing is nothing more that a map to success, but very few realize this and I believe intelligent people can see this more clearly than the rest of us.