Since they've updated Play to Play 2, the EWQL libraries have been running great in Sonar 8.5 for me, in both the x32 and x64 versions.
I don't own FabFour (yet), but I do own a number of their other libraries. Before Play 2, Fast Bounces and Freezes were not reliable in Sonar. Many times you would get dropped notes and were forced to do real-time bounces, which were not always successful either.
Now, with the new Play 2 engine, Fast Bounces and Freezes work like a charm. (i.e. I haven't had one fail yet.) This is a huge boost in my workflow. I always found the quality of their virtual instruments worth the extra effort to make it work, but now that it's fixed, it's a joy to work with.