Jim,
I did the group hike to Thor 2 days after the huge "Monsoon" in October, and two of my buddies used minispikes for the ascent. The big however, here, is the fact that AxeMan had cut nice little steps into the snow with his AXE (thus his name) so that there was no verticle gripping required.While I did not own spikes at the time and was able to make the climb without any extra grip, my buddies had an easier time with the spikes. During that same weekend, one of the guys summited Whitney using spikes, but had to use crampons coming down. I would never consider minispikes as any sort of replacement for crampons, if the conditions call for crampons, however, they are great to carry as a just-in-case item for marginal conditions. As far as the Ice Axe goes, you will see a flurry of "do you think I need an ice axe?" posts just before any snowy ascent of any of the WZ peaks, and there will be many different answers. I, of course, just ask Bob R. and I would fee comfortable with his answers under any circumstance, because I have hiked with him and I like his style and trust his judgement...and he is on the mountain very frequently. You have to trust the people you are getting advice from.
B