I wanted it, didn't get it when I bought my vehicle, then regretted it. I wanted the flat floor for sleeping in the back and the ability to extend it out for use as a tailgate. I ended up buying one from another member and installing it myself. The trick is finding someone selling one within driving distance, because they are bulky and shipping would probably make it cost prohibitive. I've only had it in for a month and haven't yet used it for the reasons I wanted it, but I've already found it very useful for loading and unloading heavy loads. Definitely helps keep the pants cleaner too since you don't have to lean over the rear bumper to get to the back. The extra storage space under the tray and in the new compartment between the tray and the seat back are just bonus features.
I'd say get it, try it, then sell it to someone else on here looking for one if you don't like it. You can probably get most of your money back out of it.