Which saddle is right for me? A Consumer's Dilemma

Wool versus foam: Foam panels are manufactured in pre-made molds in an assembly line manner which focuses on production and cost reduction over form and fit.  While foam panels conform to a horse's back statically, they do not have the elasticity to allow them continuous conformation once the horse is movement. Foam panels cannot be adjusted to fit a horse when his body changes and this can lead to discomfort and even injury of muscular tissue. 
Wool on the other hand conforms to a horse's back statically and dynamically. Because of its nature, it also disperses the rider's weight over a broader area, assuming the correct design and fit of the saddle.   Because wool flock consists of long individual strands it can easily conform to the polymorphous shape of a horse's back, and the biggest advantage is the ability to adjust a wool flocked panel to match the changing shape your horse.

Plastic or adjustable trees versus natural wooden ‘spring trees':
The initial thought of an adjustable tree, or a plastic tree being more versatile or cost effective than a natural wooden tree is a normal one.  However, if one examines the properties offered by each of these materials in the long run, the wooden tree may be the most cost effective.  When observed closely and placed side by side, the metal trees included with adjustable
saddles do not offer the proper clearance needed when actually placed on a horse to avoid contact with the withers. 
Plastic trees are made in/from molds. The initial financial outlay to create a mold, necessitates a large amount of production to recuperate the initial investment, and a defective mold is often not corrected due to this cost. Plastic trees are susceptible to vertical flexion and torsion which can cause serious injury to a horse's back. 
Wooden trees, which are hand made from laminates such as beechwood, can be tested for flexion and torsion prior to production thus can be easily corrected should there be a problem. The term "spring tree" refers to the spring steel reinforcement of the tree allowing for dampening the pressure applied to the horse's back while controlling the degree of vertical flexion. 

Educating oneself is paramount in making the decision of which saddle to purchase.  Many of the world's top riders; Margie Engle, Robert Dover, Courtney King-Dye, Edward Gal,
Eddie Macken and Leslie Burr Howard for example, have chosen saddles made in
the traditional manner perfected over hundreds of years of saddle making.