Help me understand oscilloscope peak acquisition mode

[AJ528]

No need for argument on any side...

R&S has one display representation. Siglent has other. On every "vertical double point" R&S plots in time, Siglent will plot two samples, one Max other Min. When viewed at some normal timebase they will show exactly the same.

This super high zoom ratio displayed was very useful to see what scopes actually do. But in practice it is not supposed to be used like that.
Purpose of Peek detect mode is to show very short pulses on longer timebases. If you look at main (not zoomed window) both scopes show a spike, positive and negative (that would not be there in normal mode and slow sampling) and that is extent of it's usability.

On both RTB2000 and even more on Siglent SDS2000X+ (that has order of magnitude more memory), Peak mode is pretty much unnecessary.
I know I didn't use one in ages...

Yeah, this is my takeaway too. However I am glad I now understand how Siglent implements this mode. It's always good to be aware of quirks.

I think the R&S way of displaying peaks is more accurate, but they do both convey similar information.