The cryoed Hubbell 5262 that Virtual Dynamics is doing has every right to be an excellent receptacle, although I haven't heard one. It is simply a 15 amp version of the Hubbell 5362-the only difference is that the 5362 will accept a 20 amp plug. Other than that, the 5362 and 5262 are built to exactly the same standard and are identical.
The Hubbell 8300 has a different face material and its contacts are nickel plated; apparently the nickel plating will give the receptacle a slightly more forward presentation. Some will say that the nickel contributes a "brightness".
The other question relates to the actual cryo treatment. The World Power receptacle is subjected to a longer than usual cryo treatment; whether this translates into better performance, I can't say because, once again, I haven't heard the VD receptacle. The VD receptacle also offers some form of contact enhancing treatment from what I remember, and the World Power comes "burned in" to substantially reduce your "burn in" period.
Like everything else in life, you pay your money, you take your chances!