Hi misterm,
Welcome to the Mattress Forum! 
I’m not quite sure what you’re referring to as far as who “might be legit”, so I’m sorry that I can’t comment upon that. As for registering, this is a moderated forum with rules of conduct, so registering is a requirement of participation.
You do bring up some excellent points about the marketing that purports to be mattress research online and the real reason behind many of these sites simply to get click-throughs and drive sales, with many of the sites simply repeating information from those manufacturer’s web sites. You can see my comments about many of the so called “review sites” which are really just revenue sites that know little about mattresses or mattress materials) in post #11 here and in posts #4 and #6 here.
See the reply below from Novosbed regarding clearing the cookies from your browser to fix that error, or for alternate methods of purchasing a mattress from them.
Phoenix