From my own experiences only, there are pros and cons to both. Although each division does start in their own wave so the 5K part of the course is equally crowded for all but the fastest runners, individuals have always been the first wave, so the scavenger hunt part of the course is less crowded for them than individuals. That also means they tend to finish the whole things first and are first to get in lines for rides and the party is less crowded/chaotic for up to 30 min until the other waves catch up.
However, if you get stumped on any of the scavenger hunt stuff, being with a team mate is a great help. Two minds are better than one, and individuals are specifically told not to help each other. So having a teammate figure things out with you can be a real help. That also can hold for the running parts. If your partner is slightly faster, or they motivate you, you could end up with a better time trying to keep up (my case the second time around. I was exhausted afterwards, but trying to keep up with my partner made me get a new PR time).
I also wanted to add that for those nervous about being new to running, don't let me scare you. I had only been running for 3 months (C25K myself) before the first run and my fastest ever 5K time is still over 30 min. Being DISBoard folks, being park veterans, honestly that will help you in this event as much as any running ability. I made up all sorts of time in the scavenger hunt just by knowing the layout of the park. Not needing to consult a map to know which way to get to "Africa" was huge. So, if you want to do well, don't just practice running, but know the layout of the park.