I keep a spreadsheet log of the split times from record rounds, which allows for some simple analysis and comparison of times. This document summarises the results.
The data is based on trackers, Strava traces and published actual schedules. Some sources include seconds; others just minutes. Either way, it is best to treat the table as a general guide rather than precise record. The final column in the men's and women's sections is the fastest split of any man or woman (respectively). Aggregating these splits gives a fun, if wholly notional, 'fastest round'. Assuming no rest stops (!), this comes out as 11h 49m for the men and 14h 21m for the women.
In researching the new version of 42 Peaks, I compiled a list of a number of 'notable' rounds. There is no strict definition to this; it is simply rounds which felt of certain historical importance.
In case useful for others, the table below summarises these and their primary statistics. If anyone is interested in further detail on any of these rounds, I'd be very happy to help provide sources.
In the table, 'Season' denotes whether the round was a winter round or not [N (summer); W (winter); MW (mid-winter)] and '42 peaks' is the page reference in the new version of the book.