When we got ds's Explore scores, we did chose to get IQ testing done. We didn't think he'd qualify and that was easier to us than a portfolio.
We had the IQ testing done by a grad student so it was cheaper. Again, we were testing out of curiosity and more a thousand to one shot. I recall dh expecting scores to be much lower than they were.
The testing was useful to me and gave me some additional permission to let go and move faster in some areas with ds.
We haven't traveled to Reno, but I've gotten good information from other parents that has been helpful.
So I'd say there's definitely no harm in applying.