  To date, a conclusive detection of quantum speedup remains elusive. Recently,
a team by Google Inc.~[V.~S.~Denchev {\em et al}., Phys.~Rev.~X {\bf 6}, 031015
(2016)] proposed a weak-strong cluster model tailored to have tall and narrow
energy barriers separating local minima, with the aim to highlight the value of
finite-range tunneling. More precisely, results from quantum Monte Carlo
simulations, as well as the D-Wave 2X quantum annealer scale considerably
better than state-of-the-art simulated annealing simulations. Moreover, the
D-Wave 2X quantum annealer is $\sim 10^8$ times faster than simulated annealing
on conventional computer hardware for problems with approximately $10^3$
variables. Here, an overview of different sequential, nontailored, as well as
specialized tailored algorithms on the Google instances is given. We show that
the quantum speedup is limited to sequential approaches and study the typical
complexity of the benchmark problems using insights from the study of spin
glasses.
