There have been many threads and there's always disagreement. I maintain that it depends on your application. A mobile-mount winch has some drawbacks but also some benefits.
Benefits: not exposed to elements every day, not available to steal/Jeep has lower "theft profile", cheaper than steel bumpers, lighter than steel bumpers.
Drawbacks: possible loss of approach angle, awkward to carry/install, not as strong as a hard mount.
I say "possible" because this all depends on how your receiver mounts. Mine puts my winch mount 20" from the ground and right up against the bumper. I have never hit it on anything on the trail, only once I scraped it on a rock when I was posing for flex. As for the receiver being weak, I find it funny that the same die-hard Warn fanatics would call my Warn receiver hitch "weak". It's made with beefier, thicker material than my OEM Class IV hitch is. Companies like Fawkes Offroad are developing/producing even stronger front receivers with ratings of 14,000 lbs.
As for mounting, people are going to say "are you really going to mount that up when you are stuck?". No of course not! You put it on before you hit the trail and take it off when you get home.
Now if you were building something crazy for black diamond trails, a really hardcore off-road build, definitely go with a hard mount. But if you are building a rig for mild and moderate trails that doubles as a daily driver, there's nothing wrong with a mobile mount as a insurance.
Now for some specific recommendations - the winch mount you posted is specific to the Powerplant winch. Make sure that the cradle you choose has handles and a fairlead mount and uses 1/4" construction. Harbor Freight mount is way too thin. The Promark/TuffStuff/Generic/SmittyBilt unit has quality control issues, I received two defective ones. It seems hard to find a good quality winch mount. There seems to be good mounts available from Warn, Superwinch, and Curt. Don't skimp out here.
As for winches, you can't really go wrong with the M8000 or VR8000 from Warn, especially if you go mobile mount. The M8000 is strong, reliable, and light, especially if you put on synthetic rope.