Haven&#x27;t spent enough time with Racket, but my understanding (correct me if I&#x27;m wrong) is that you won&#x27;t squeeze as much performance out of it, and performance is quite important.  I&#x27;m also quite partial to Lisp&#x27;s condition system -- I don&#x27;t believe Schemes can support something that comprehensive (a trade-off for having nice things like call&#x2F;cc, I think?)