First of all, pricing is the first thing that will come to a chef's mind when he is picking the products. When the establishment is financially well off, then they will be able to purchase higher quality chocolates. When they're in a bit of a struggle, they will go for the lesser quality of chocolates (I've even seen people go as low as hershy's)
Second of all, It depends on what you're making. If you are making ganache or truffles, one would choose a mid-high quality of chocolate (eg. callebaut, or cacao barry if they have the money) Because you are basically blending other products in which takes away some of the attributes of the chocolate so there's no point for using the best.
Same with showpieces, you are using ALOT of chocolate that nobody is going to eat and will probably be remelted and reused for other applications. so you do not need the highest quality chocolate.
When you're making pure chocolate bricks, you can start going into higher quality chocolates like cacao barry or valrhona. it's a small amount of chocolate that you can charge a high price (can go up to almost 500%) for and you get the pure quality of the chocolate.
How chocolate is ranked depends on how pure your chocolate is. by pure I do not mean cocoa percentage. I mean How much of it actually derives from a cacao bean and if not using products that derives from cacao beans (milk and white chocolates), how high is the quality of the additives (milk powder, sugars). There are also different quality of cacao beans and that also comes to play. In the end, you are looking for the smoothness in texture of the chocolate as it melts in your mouth.
I would say the industry collective agreement on the highest quality chocolate would be valrhona. the others could be debatable or by preference.
To the average consumer, they would not be able to tell the difference between the different quality of chocolate, even most chefs do not have the ability to tell. Unless you are a master chocolatier or you actually study chocolate for a living, you would not be able to tell the quality difference. If you blindfolded me and ask me to name the different chocolates, I would not be able to tell.
Some chefs advertise that they use a certain high quality chocolate so they can boost their prices up a little.
In the end, it all depends on the skill and technique of the chef. No matter the quality of the chocolate, If you can transform chocolate into a wonderful product (mousse, truffles, bonbons, etc.), the consumers would love it regardless of the quality of chocolate used.