I have mixed views on this one. My daughter has used one of these cases with her MacBook for more than four years (including studying overseas with all the associated air travel). That laptop is still going fine. My son has the same case for a 13 inch MacBook Pro. His laptop, in the same type of La Robe case, just fell about two feet off a sofa. The screen is now thoroughly cracked - essentially shattered. I don't think the distribution or choice of padding is adequate to give any useful protection against an edge impact, which is the kind of shock that probably does the most damage. I simply don't know anymore what sort of case (if any) really would be effective. We chose a shapefoam padded case over the thinner rubber ones in the hope it would provide more shock protection. Now I'm unconvinced.
Sadly, the range of purchase options available for credible shock protection is not as broad as I'd have expected, and I can't find any really convincing reviews by people with real packaging engineering expertise. Surely a market opportunity for someone here.