I work for a engineering company that designs post tension, conventional rebar reinforced, and pier and beam slabs. We do engineering across the state and have over 350,000 homes on the ground, not including commercial structures. There is really no definite slab design that will work 100 % of the time given the huge variability of Texas soils.
Pier and beam has the benefit of having easy access to plumbing under the slab but also increases the probability of pest problems and radon exposure. The underside of the slab needs to be well vented and the piers must be drilled deep enough into bedrock or into undisturbed soil to prevent excess movement of the slab.
Traditional "floating" slabs are more popular due to the construction costs associated with drilling piers and the additional concrete to fill them. When properly reinforced, a slab on the ground is just as sturdy as a pier and beam home. The only negative is the cost of repairs to plumbing issues under slab. It is really an issue of whether or not it is worth the additional up front cost of a pier and beam foundation to avoid the possible costs of future plumbing repairs underslab. If plumbing is properly installed you should get several decades with no problems to contend with. IMHO a slab on the ground is going to work well for MOST homes, large, custom floor plans notwithstanding. Soil boring and good engineering should help make the best decision for you.
