Over the years these shops have been discussed a few times, with much of that discussion centering around the hassle of getting back the amount that was wired. The current MSC brags that it guarantees the return of the funds, which was often problematic with the old MSC. (I'm of course referring to the legit WU shops routinely conducted by a well-known MSC that require wiring $20 and immediately asking for it back. Anything outside of that, or their other scenario which doesn't involve sending any money, is likely a scam that should be avoided.)
I did one last month. The location refused to give back any of the money, and had me call, but that didn't work either. I simply stated how much I was owed in my report. A few weeks later, without any additional prompting from me, I got an email with a code which I could take to any WU. When I went to a location there was an issue with the code and the employee there had to call, but after about five minutes everything was taken care of and I left with all of the funds I was owed.
The bottom line is that I'd do the shop again, but the fee I'd do it for would have to warrant the liklihood of my going back to an agent and waiting a few minutes to get the refund. Luckily for me there are three agents within walking distance of my home, but for others this might be a major detractor.