Instant spawn in slayer (and oddball) and no option to remove it is the only thing that i can see being capable of killing competitive H4, there is no map flow like in previous installments and setting up can be a complete hassel when the person that you killed just spawns and kills you because you are still 1 shot.
There is an option for repawn time, but they can still just tap the button to spawn instantly.
I, and maybe not all but many others would like to see an option to have a spawn time.
I am NOT saying it should be forced, but the option would greatly benefit those that wish to use it in customs cough MLG cough
Besides this complaint, i see very little wrong with the game 
Please and thank you 
(i try to be nice, but will still be flamed) <3