Gail,
I work in a middle school in Stamford, CT and I genrefied our fiction collection two years ago. The kids love it! They are learning how to use the online catalog to see what the 'sublocation' of the book is and then independently go to the section marked with that genre to look for the book by author's last name.
They say the thing they like the best is that when they don't really know what book they want to read or which author they like best, they can just go to the section, like 'sports' or 'humor' and find something quickly.
On the flip side, teachers who are looking for books by specific authors are frustrated because they have to go through the extra step of looking in the online catalog to see where that author's book is genrefied.
I chose not to genrefy the non-fiction section, but I did add shelf labels with Dewey numbers and the topic for that section so kids could find their topics without having to 'look up' the correct Dewey number.
They know how to use Dewey, but they prefer using the genrefied system especially when looking for an independent reading book. Here's a doc with pictures for your reference. Good luck!
https://docs.google.com/document/d/1ZmP_9ISB3s3BBY6yu8Wwwco5SUlvUe-5VwqEkwhgvlc/edit?usp=sharing