I agree with the overall thrust of this but this...<p><pre><code> "Even after they made their case, we were fairly
direct in asking them why they couldn't do a
simple recompile and use SSE instead of x87.."
</code></pre>
This is hardly a simple recompile. Sure, with most codebases you can simply "flip the switch" in your IDE or at the command line, rebuild, and everything will work fine. Doing this in production software requires re-testing everything from the ground up as (especially in performant code, and different optimizing scenarios) a change like this can have side effects.