I make a point of reading Possession at least a once a year, along with Middlemarch, Moby Dick and Pride & Prejudice. Truly, one of my top five Desert Island Novels. It hits me where I live. I've read the Frederica Quartet twice and find it thoroughly engaging and fascinating.
Would love to post and chat more about Byatt's work, if there is still interest out there. There is so much to say.