I'm admittedly a novice in this field, but I have read that, while the D-wave (one) is an interesting device, there is some skepticism regarding it being 1) useful and 2) actually a 'quantum computer'.

For example, Scott Aaronson has expressed multiple times that he is skeptical about whether the 'quantum' parts in the D-wave are actually useful:

It remains true, as I’ve reiterated here for years, that we have no direct evidence that quantum coherence is playing a role in the observed speedup, or indeed that entanglement between qubits is ever present in the system.

Exerpt from this blog.

Additionally, the relevant Wikipedia section on skepticism against the D-wave is a mess.

So, I ask:

1. I know that D-wave claims to use some sort of quantum annealing. Is there (dis)proof of the D-wave actually using quantum annealing (with effect) in its computations?

2. Has it been conclusively shown that the D-wave is (in)effective? If not, is there a clear overview of the work to attempt this?