Did a quick search and didn’t find anything, excuse me if it has been posted already
The Fast Hands trait induces a 5 second weapon-swap cooldown whenever you drop a bundle or jump into water while in combat. This is an issue when fighting in PvE with bundle mechanics(Liandri the Concealing Dark), or in WvW when jumping into water and having to wait those 5 seconds before swapping to your appropriate weapon set. Not a massive issue, but certainly noticeable. (Perhaps also PvP: Kyhlo and repair bundles).
This of course is opposed to not having the trait, these actions don’t induce a weapon-swap cooldown.
Thanks for reading.