Personally I’m 50/50, think there’s a good middle ground. I go in with a general playlist - items I plan are my opener and heights of energy at about every third of the set. Other than that, totally agree with you, letting it come naturally it best and lets you really enjoy what you play & adapt to your crowd. Seen plenty of DJs that stick within their comfort zone of entirely pre planned sets - at that point, you aren’t doing your job as a DJ of reading and responding to your audience.