What an extremely important point you've made here about drabbles. So not for the casual fan...you do have to know the characters and their personalities to be able to fully enjoy them.
And yes, when a reader tells me I've "nailed" someone's voice or that the drabble is IC, it means the world to me. And when they say, "I could picture the whole thing" or "This should have/could have been on the show," I am over the moon. To be able to show the Queer as Folk world that's in my head to someone else and have them "get it" is priceless and frankly, it's what keeps me writing them.
I have 26 drabbles from other writers favorited in my memories. Your untitled GLC drabble tops that list, hands down. I still can't read it without tearing up and *feeling* that love between Daphne and Justin *AND* feeling the pain everyone suffered from the bashing.
Another favorite of mine is Tell Me About Ibiza by vamphile. It's graceful and elegant and completely took the prompt, which was to use a series of "spooky" words, to an unexpected place.
frantic_quest, a fairly new drabble writer, was able to take the vacation prompt to an unexpected place in Diversion and that's what made it so memory-worthy for me. Vacation brings happy to mind and we got something way different from that drabble.
For me, that's really a kicker for a drabble. If someone is able to take a prompt or an idea and take it to a really unique place, or to write about something you wouldn't expect from that prompt, I am totally enthralled. That little kick, that punch in the gut, whether angsty or happy or silly, really makes a drabble work for me.