&gt; the paper ignores the reason why people kicked and screamed for the functionality to begin with<p>No it doesn&#x27;t. The explicitly talk about this in section 7: &quot;The acceptance of Typed Racket in the commercial and open-source Racket community suggests that (some) programmers find a way around the performance bottlenecks of sound gradual typing.&quot;<p>&gt; Reticulated Python is still an order of magnitude faster than Ruby<p>Are you suggesting that a slower variant of Python is <i>ten times</i> faster than Ruby? That doesn&#x27;t match my experience. For what it&#x27;s worth, Ruby outperforms Python in some benchmarks: <a href="http:&#x2F;&#x2F;benchmarksgame.alioth.debian.org&#x2F;u64q&#x2F;ruby.html" rel="nofollow">http:&#x2F;&#x2F;benchmarksgame.alioth.debian.org&#x2F;u64q&#x2F;ruby.html</a>