I'm glad this was a novella. While the plot is interesting and the writing is just superb the entire concept of "oh she's a vampire, no wait, she's a lesbian vampire" gets tired quite quickly. However this is one of those works that you have to read just off of its sheer influence alone. The trope of the lesbian vampire was so important in early horror movies, B-movies and especially Giallo horror. 
 (Also I love the fact that two of the most pioneering and influential works of vampire fiction were written by two Irish guys, go us!)