For me, it wasn't a case of pages loading slowly; the problem was that loading would completely stop 10-15% of the way in. The only solution was to quit and relaunch Safari, and even then, the "fix" would only stick for 15-20 minutes. Every site was impacted.
Since following the solution in post #14 of the thread referenced in my earlier post, Safari's been humming along without problems. Not sure why it suddenly slid off the rails a few days ago, but hey---I"m just happy to have it functional again.