Advent,

As you can see, opinions vary. As for me, I limit the use of CA hinges to smaller (<=.40 size) aircraft, and have not had any failures (Knock on wood)
If you read the article that was linked by MinnFlyer, you will notice that there is a reference to using a crayon in the area that will do the flexing. It does in fact protect the hinge material form the CA. The reason this is done is that CA is essentially liquid Acrylic. Although Acrylic is tough, it is also brittle. During the initial flex/CA application process, the unprotected hinge material fibers (which are typically a woven material or a laminate of woven material and Nylon film) becomes filled with CA. No harm, no foul............so far. When the surface is flexed back the other way, the familiar snap occurs. This is the CA and some of the hinge fibers breaking, somewhat weakening the hinge. [:@]This is where the crayon comes in. The wax does not allow the CA to penetrate the hinge material.

IMO, if you are looking for a bit of extra throw on the Somthin Extra, or are looking for a hinged surface with little or no resistance, you may want to consider hinge points or pinned type flat hinges that are offered by companies like DuBro.