I agree, many important tactical options are reactions in 5E. Since you only have the chance to use one reaction per round, the slowdown to combat seems much exaggerated by the detractors. Once your character blows their reaction there shouldn't be any further prompts for the round for that character. There may be a handful of situations where you are saving your reaction for a very specific situation, but the times where even that would greatly slow down combat would be far and few between.
