A lot of folks, particularly those new to competition cooking, cook what they like. Nothing wrong with that, but know that when you cook for judges you're cooking to please the broader general public. If your tastes love salt, that's not good. If your tastes are like mine, you'll have food TOO spicy for the average Joe. One would think I'm making the argument for commercial rubs. There's certainly something to be said for them. However, I never found one that I couldn't do better. Perhaps because when doing my own, cost was no object. As Gavin said, make sure they're fresh.
Try them, as you did, on your friends. Also, try them on your friends when they're not starving to death and when they're stone cold sober. Try multiple recipes at the same time, let them judge them against one another, you'll find what works best for you.
Hance - Lake Dogs Cooking Team - MiM/MBN/GBA CBJ and comp cook
Lake Sinclair, GA (strategically about an hour from darn near anywhere)
Started competing in chili cookoffs back in the 1990's and have competed in more than I care to count. I became a CBJ in MiM in 2005, then MBN and in GBA in 2010. I've probably judged 130+- BBQ comps (sanctioned and unsanctioned) over this time. That said, I really enjoy competing more than I enjoy judging, and hope to get back to doing 4 or 5 a year in the near future.