VMware vCloud is quite a complex application as you have already found out; therefore, it is extremely important to create a stable, simple, and expandable design.
Design is one of the most important things of a vCloud deployment; it can have long-lasting financial implementation. To explain what is going on, I will use the following example:
When you plant an apple tree, you can see it grow and it will bear fruit; this fruit will be small to start with, but will grow with the tree. As time passes by, the tree grows more leaves and branches, and then the apples start to shrink.
A design is like a guide for pruning, fertilizing, and the poles that guide the tree growth. It makes sure the apples stay big and juicy.
A design specifies how and why things are done, how things fit together, and specifies concepts that need to be adapted. Some typical features one should look for in a vCloud design are:
How is vCloud integrated with vSphere?
How many Cells are used and where load balancing...