You can create much tougher classical competition by writing highly optimized code that accounts for the sparse connectivity structure of the current D-Wave chip.
Why should optimized code "account for the sparse connectivity of the D-Wave chip"? If the contest is to solve an optimization problem, then the "classical competition" doesn't need to know anything about the D-Wave. The only reason a competing code would need to model the D-Wave itself would be if it's simulating how the D-Wave solves an optimization problem-- in which case comparing the times taken to do the optimization is hardly meaningful.