Interesting, IIRC Rails 3 works best with 1.9.2 I'm going to run the benchmarks on 1.9.2 vs. 1.8.7 and see how they fare.

The article mentions, "REE 2011.03, which is Ruby 1.8.7 patchlevel 334". Not sure if this was a recent edit or not.

ree is 1.8.7 - Rails3 doesn't work with anything below 1.8.7