Deans are fine IF they're the only connectors you're using. I don't like seeing Deans AND 4mm bullets being used at the same time.
I run Protek solid 4mm connectors on mine since they come with my batteries. I've yet to have an issue. However I'm always checking them for a snug fit and any burn marks. If I see even one, I replace it.
EC3 connectors are good also but they're hard to pull apart in my opinion.