[Taken from the 10.1.5 Patch Notes]: Fixed an issue where large guild history cache files were causing zone change load times to increase by several seconds.

Now, to be fair, the load time increases happend even moving from outside a bank to inside one, as well as zone changes. And "several" seconds is an understatement, and could be as much as 30 - 120 seconds.

However, patch 10.1.5 did fix this issue, and load times were more pleasant - after testing from reverting guild cache settings back to their defaults. However the problem seems to have re-emerged after today's patch (10.1.7). Having gone back to the altered settings - being found in the UserSettings.txt file and changing the following numbers to 3, limiting the cache size:

SET GuildHistoryCacheMaxNumberOfDays_ava_activity "3"
SET GuildHistoryCacheMaxNumberOfDays_activity "3"
SET GuildHistoryCacheMaxNumberOfDays_milestone "3"
SET GuildHistoryCacheMaxNumberOfDays_trader "3"
SET GuildHistoryCacheMaxNumberOfDays_banked_currency "3"
SET GuildHistoryCacheMaxNumberOfDays_banked_item "3"
SET GuildHistoryCacheMaxNumberOfDays_roster "3"

It did fix issue as it had done previously, but this time the guild cache file did not reduce in size, as it had done previously, but the load screen times do improve back to normal lengths for internal zone changes - moving in/out of a bank - but are still much longer than before the patch for external zone changes.

For context, a 3MB file, causing a 30+ second increase to a normally less than 5 second load time, on a modern PC should not be happening.