I have one that I picked up from Harbor Freight a few years ago. It has come in handy, nice to keep dirty stuff out of the Excursion, or to big to fit, but not so big as to need the trailer....
I have one similar to this..... I bought mine 5 or 6 years ago.....
Hitch Cargo Carrier - 500 lb. Capacity
Mine has a mesh floor, not the open floor this one has. I have carried 10+ large bags or topsoil, I have also carried a washer and dryer on it over 300 miles.... Mainly what I have found is, if it will fit on it, it will carry it.... I know that is not a fit-all statement, but it is what I have found. The only thing I have noticed with any of them, they will teter-totter on the pipe going into the receiver on the hitch... so just keep that in mind when you are loading it.....
Also.... remember these do not have lights... and depending on what you are carrying, you could cover up the lights on the truck..... Everything that I have carried has not.... but I have seen some on the road that are covered......