After being in the triathlon scene for many years I have had the opportunity to try a number of wheels, some of which I like and others that I do not. Speed Theory is having a huge blow out on 2008 Zipp wheels, so I decided that I would post my thoughts on race wheels.
Depth vs weight:
There are two main reason why people use race wheels: decrease weight and to improve aerodynamics. Depending on the race, aerodynamics or weight may be a more important factor. Some wheels, like a disc, have incredible aerodynamics, but are not allowed in road races/crits and are to heavy for hilly courses, and hill climbs. Typically, the deeper the wheel, the more aerodynamic it it. On the other had, the deeper the wheel the heavier it is. For this reason, the most popular wheels are around 50-60mm in depth. This allows excellent aerodynamic benefits while still maintaining a lighter wheel that can be used on all courses. Shallower wheels, or even non deep dish rims are excellent when weight is the main concern and these wheels can also be much more responsive.
Tubular vs. Clincher:
In my experience most people who go with clincher tires do so as a defalt. Almost everyone is familiar with clincher tires and like the convenience of being able to just change a $8 tube as supposed to a $120 tire everytime they get a flat. The reality is that once understood, tubulars are not difficult to deal with and less prone to flatting (no pinch flats). Like most things, learning to tape or glue on a tubular is a skill that you only learn with pracitce. If you are willing to take the time and learn how to do this, you can save a lot of weight in your wheels. The weight saved on tubulars wheels is all in the rims, meaning rotational weight. In your wheels this is the most important weight to minimize because it is constantly accelerating and therefore requires a lot of energy to keep it continually moving. For example Zipp 404 tubulars are 1250g and Zipp 404 clinchers are 1615g. This is a huge amount of weight you can save, just by chosing one wheel over the other. By going tubular, you can race on an aerowheel, while maintaining the weight of a climbing wheel. My recommendation is to tape your tubular instead of glue it. This allows you to change your tires during a race or right before a race/ride and not have to worry about letting the glue settle. In my opinion tubulars are a much faster wheel at the same price and can be used by everyone.
What I use:
My favorite wheel to race on is the Zipp 404 tubular. This wheel is around 1250g and is an excellent balance between aerodynamics and weight. For me, racing on the draft legal ITU circuit, a disc is not an option and many of the courses have sharp turns and hills. For these reasons, I want a wheel that is responsive and lightweight, while still giving me the benefits of added aerodynamics. Tubular is an obvious choice for me because I want the decreased weight and improved performance. It is a race wheel afterall.