I predict that, ceteris paribus, people who just go do things will outperform people who talk about IQ all day. :)
All day, sure- the trope of Mensa underachievers is based in reality. But people who did some very awesome things reserved some time for IQ, and I think avoiding talk of IQ in order to avoid the low-status of Mensa is as silly as talking about IQ because of the high-status of intelligence.
Based on a diversity of high functioning folks I have seen, I think single parameter models are a hopeless waste of time.
This isn't the right comparison, though- the question isn't diversity among high-functioning folks, but the difference between high-functioning and low-functioning folks. (Now, social skills, energy, and so on are important parameters that a more complete model would have- but that doesn't mean single parameter models aren't worth the time they take to populate.)
I've never heard of anyone saying "I thought that person was really intelligent, but they turned out not to be", and when there are scandals about people with fake credentials, they don't seem to come from people with fake credentials making mistakes-- instead, someone checks the history.
It seems to me that you can find out a lot about people's intelligence by talking with them a little, though I've underestimated people who were bright enough but didn't present as intellectual.
The real problems are with identifying conscientiousness, benevolence, and loyalty-- that's where the unpleasant surprises show up.