For me, too, grim endings are a preference. Total submergence, a close second. I always feel cheated if the victim escapes. Unless... and this is the exception.... she is a good girl and yeah, earns her escape. Or gets away from a bad girl who goes under instead. That last one really works...
The sexual element never even occurred to me until I found the community in 1998 and started reading the tales. That did open a whole new side for me, one in which I admit I have a lot of fun exploring
But that doesn't take away my preference for the ladies in peril element, which remains my main reason for enjoying qs scenes.