I've only had one limb failure in the last 15 years, and that was, ironically enough, a Hoyt solid limb bow.(Superslam Supreme) The limb split at one of the forks.

I do think that split limbs bend more evenly, since they don't need the reiforcement at the fork of the limb. Some solid designs (PSE and others) have such a long reinforced area that is very thick that only a small part of the limb actually flexes and stores energy. That has to be hard on the limb, but the materials seem to be able to take it.

True, solids need not be so wide, don't give brush an extra chance to get caught on the bow, don't require moving Limb Savers to press the bow, and probably do a better job of keeping eccentrics lined up through the draw and release cycle.