Rim height: aerodynamics versus climbing ability
A high rim design makes wheels aerodynamic, e.g., particularly fast on flat ground and downhill runs. On the downside, taller rims are heavier and more susceptible to interference from crosswinds. If you are a rather heavy rider, then you have some advantages here: your bike will be less susceptible to wind and a higher wheel weight will have a relatively lower impact on the system weight. In this respect, you can opt for high rims. These are also stiffer as a rule, which affords you an additional advantage.
If you are more of a hill climber, on the other hand, then a little more restraint is called for when choosing the rim height. When in doubt, choose the flatter profile. It is usually lighter and less susceptible to wind interference, which works to your advantage.
The following applies regardless of ground conditions and weight: choosing a slightly higher rim at the rear than at the front brings stiffness to the rear wheel and improves aerodynamics without dramatically increasing wind susceptibility. Time trialists exploit this idea to the maximum degree: a disc wheel rotates at the rear, and the highest possible rim height rotates through the fork.