I'd been using nRelate for several years, but I started exploring other options a few months ago in prep for switching the front-end over to HTTPS (since nRelate didn't offer SSL-hosted resources). I settled on Jetpack -- it wasn't as customizable as other options, but it gave better recommendations than nRelate or YARPP on my sites. Weirdly enough, I had *just* switched over my last blog when the nRelate announcement went out.