I have completed several over the years. The visit will run from 30 to 60 minutes, with a like time report; it depends upon the MSC for whom you are working. A closing comment: If a target is involved, add $10, as they do not always work the days you are given to shop.
I did one a year or so ago and am thinking of doing another if the price gets high enough. It took about half an hour but I was the only customer and so was helped right away. The shop isn't bad. There is at least one out there that is reportedly far, far worse.
I did one of these a few years back and the salesperson would NOT let me leave. I spent over 2 hours in the store.
When I did my report, all of the requirements had been met; all of the necessary questions/answers, etc....and I was able to give great detail about the sales person keeping me for so long, even though I tried to "politely be done...." The MSC apologized and gave me double pay, which was unexpected
That was just an anecdote ^^^ but other than that, I've done them pretty often and they are easy and seem to pay okay