Likewise not supplying enough technical information for an audience which is technically aware is also detrimental. If necessary give the client different designs for each target audience. Form Follows Function. Once you have established enough information to design your exhibition system then incorporate your design around this as creatively as possible. Never try and do this the opposite way round.
Simple graphics are often the best way to convey a message.
If a design is too complicated or too subtle then it can quite often be misinterpreted, or worse, completely ignored. You can always put smaller text on the exhibition stand outlining the benefits of the product being sold - but even this should be easily read from six feet away. The bottom third of an exhibition system can be difficult to read up close - never place a key point in this area. Try to avoid designs which will cause problems when assembling the graphics. Clients may not be as experienced or as adept at assembling graphics as you are.