Worked as Advertised
It works out of the box, as advertised.
The disgruntled user who said it did not having a working user probably didn't notice the "Usage instructions" tab on the instance in the AWS console.
I'm only giving it 4 out of 5 stars because the vendor advertised "24/7/365 support". I raised a ticket on their site that I could not connect to my instance and designated the ticket as Critical. I'm annoyed that 48 hours later I still haven't heard from them. I eventually figured out my problem (it wasn't the AMI's fault).
And now I'm happily configuring the instance to my own personal preferences...
I see the comments on the earlier disgruntled user, that he was right, the vendor listened, and the vendor had already addressed the confusion before I tried using it.