Reply to DJing styles

Just wondering what style of DJing is used by people here?

Do you beatmatch live (no sync), do you use sync, do you do it on the fly, do you prep the minute details etc?

Only asking as I recently watched a Knife Party set. They DJ'd the entire set without using headphones once, but were using Pioneer CDJs. I'm assuming this was done by prepping even the littlest of details and having all their cue points etc set up and known off the top of their head, meaning they could drop cues and know exactly what went where. This appealed to me as the prep work ensures a good set and I suppose it would feel more like playing a real instrument in a way, knowing what sequence to play what cues etc and rehearsing it over and over.

However, just wondering how other approach it and whether this method is generally accepted when playing live.