I'm probably not the best person to ask on this subject, as I keep buying nylon-soled Sidis and never try anything else. They fit me well, and if it ain't broke, don't fix it, right?

But one thought did occur to me: if you're looking for more support, perhaps you might consider aftermarket insoles? I have high arches and one is higher than the other (enough that I can feel the difference). I use Superfeet in all of my cycling shoes- blue for mountain, gray for road- and they make a huge difference with arch cramping, hot spots and toe numbness.