Oh, how absolutely wonderful this story was! Excellent story-telling, and honestly, an explicit love scene just wouldn't have fit, so it's not missed. There's so much to adore here I don't know where to begin. The writing is flawless, letting the reader sink right into the narrative. (That's a more profound compliment than you might think -- some of the things I've been reading lately... *shudders*)
Your plot is a superb synthesis of Holmes twists and Potter adventure. I think I most particularly admire the way you evoke the wonder and magnificence of what the wizarding world can be, by letting us see it through Watson's eyes, similar to Harry's sense of wonder in the first books of the series.