I haven't checked in on the development of Pycket in a bit, but much of the recent work has gone into supporting linklets. Last I checked, the performance story for the Scheme and Shootout benchmarks used in the paper haven't changed much.

There are some benchmarks which evaluate Pycket's performance when applied to gradual typing [1]. Pycket does a pretty good job of optimizing the overheads of gradual typing (or at least Racket's implementation strategy), though it by no means eliminates the performance costs.

[1] https://dl.acm.org/citation.cfm?id=3133878