Bleh, my favourite part of Call of Cthulhu is how, in D&D terms, everyone is kind of 1st level and never goes beyond that. I ran a game of it yesterday for the first time, and I felt such sweet, sweet joy when one of the Investigators died instantly after being impaled by a dagger. Similarly, the major antagonist of the game was killed by a well-stabbed chopstick and a dagger.
After years of describing how multiple "hits" from D&D monsters slowly "chip away" at the large health pools of adventurers, it was the most refreshing thing to play a game that allowed for such sudden and dramatic outcomes to combat.
In CoC I don't have to worry about balancing every encounter to be winnable. I don't have to ask for Initiative rolls, I don't have to look up how much loot the players should be getting, I don't have to build monster ecologies, I don't have to draw dungeons replete with farcical traps, I don't have to read through five pages of pseudo-fantasy backstory full of cliches about orcs...
D&D is one thing. CoC is another. Like a person who wants to be sane and a tome of eldritch lore, the two should not mix.