With the exception of the slides, how might the presentations differ from a one-on-one pitch where you still might only have the same two-three minutes to convey the same basic info? I would image investors are very busy and would often want brevity regardless of the venue.
One on one pitches are more conversational. So the slides are designed to be something you have a conversation about, not something you simply present.
It's really the short Demo Day type pitches that require the most design. A Demo Day pitch can't leave obvious questions unanswered, because there is no chance for anyone to ask them. A pitch deck for an hour long VC meeting doesn't have to be so watertight, because if investors have questions they can ask them.
