What strikes me is not the bandwidth achieved but the precision of the technology to aim the laser. 19 million miles is a great distance to successfully aim a beam of light. As this technology develops, real time communications with objects in orbit like around Mars will be possible.
No, it's not slow, at all. It's the speed of light.
Unfortunately for us humans, we are a relatively fast form of life, when compared against the scale of our solar system, much less our galaxy, even when communicating at the speed of light.
I'm wondering if we will need to tweak our Internet protocols to include interplanetary time? I would imagine mirroring would be much more important. Because light can only go so fast.