First let's dispel the misconception that solid wood flooring is "real" wood and engineered is well...not. Engineered wood flooring has a real wood veneer on the wear surface, and depending on the method used to cut the veneer, it is indistinguishable from a solid floor once it is installed. With that behind us let's take a look at the construction of both.
Now let's take a look at solid wood flooring. Looking at the profile you can see both are similar with the exception of the solid being, yep you guessed it ...solid. This provides an extremely strong product that cannot delaminate which is possible with engineered wood. Delamination is when the layers of engineered wood flooring "come unglued" so to speak. Water and moisture are the enemies of both solid and engineered. While engineered wood is more stable in regards to atmospheric moisture, a solid floor actually has the potential to "flatten" out after a water leak, i.e. ice maker leak, dishwasher overflow, etc., once the moisture has dried out. Therefore eliminating the need to replace the floor.
Both engineered and solid wood have their advantages and disadvantages. However, it is my most humble opinion that engineered comes out ahead for several reasons. In addition to stability, engineered wood outshines solid when it comes to the availability of prefinished textures and treatments. This includes but is not limited to handscraping, wirebrushing, and chemical treatments; not to mention the various finishes that are used. Engineered flooring is also more environmentally friendly. Through the use of veneers manufacturers are able to yield more raw material for every tree that is harvested. In addition, a majority of the homes in Southern California have a concrete slab foundation. Engineered flooring can be installed directly on the concrete whether it is floated or glued. While solid flooring would require a plywood subfloor to be installed prior in order to nail the solid flooring to the plywood. Once you get past the "perceived" value of solid wood flooring, you have to agree that the case for engineered wood flooring is most compelling. At the end of the day which ever you choose, wood flooring will add warmth, beauty, and value to your home.