There are many race wheel manufacturers out there, they all believe their way is the right way. Each manufacturer has spent a lot of money developing its product so that it offers you exactly what its deems the best overall wheel for you. The problem is that there is no mold that fits all customers. Each person has a slightly different need.
A wheel maker picks a style of manufacture, and that limits what sort of wheels it can build. It costs a lot of money to bring a new wheel shape to market and most of these companies really aren't very large. Often a manufacturer is talked into building a new prototype wheel by an athlete it sponsors. The wheel gets ridden some, its looks are scrutinized–– often what looks cool is the most important parameter––and those elements that pertain to the speed of the wheel may or may not be tested.
Very few wheel companies actually spend the big dollars to really test wheels. Wind tunnel time is $500 an hour, and time goes real fast. Lab time for a destructive test is also pretty expensive. Furthermore, there's really no set standards to guide a wheel maker like there is in the car industry. Each new manufacturer needs to test all its competitors wheels, so it can have a database against which to compare its products.
All this starts adding quickly to the cost of the wheel. Many manufacturers don't do any of this and use marketing hype or pick some vaguely related wheel action––such as weight displacement––to preach about. You, the consumer, are still just wanting an answer so you read the ads and talk to your coach or whomever and ask for help in making the choice.
It should be said that all these marquis wheels really work. It's just that not all these wheels should be styled "race wheels." In other words, they all more or less hold the bike up, are round, stay true, and may even be stronger than your average wheel. They may (or may not) be lighter than your average wheel. But they may not be appreciably more aero than the average wheel, and especially at higher speeds that's what's most important.
