In general I think some executions are obnoxiously long, to the point where it delays the respawn timer by a non trivial amount beyond the +3 seconds. They are cool and cinematic, but with some I end up thinking "yeah yeah I got it the first time".
Now, it wouldn't be frustrating at all if the respawn timer started at the beginning of the execution. Then I'd grab my popcorn and enjoy the show. As it stands I try to always use my fastest execute if only so they can get back in the game a few seconds faster.
Yeah, I actually mean the one guy fighting four should have ONE execution he could count on to get off(if he fought well enough to execute one of his four attackers) so that he could gain health ang stamina to continue his outnumbered fray; there's a lot of controversy about revenge and maybe this dynamic could help balance the gaming up for a good fighter. As far as death penalty goes...well it's just like it is; a moment to reflect on your mistake or cuss the back-stabber who took the opportunity.
The reason executions are long is because its stopping that player from getting revived and you get a heal from it. Sure the heal could be small but how could you justify having the full benefit of not being able to revive the target with a quick execute? You could potentially execute someone in a 1v2 before the other player even has time to interrupt it?