I've got a pair of micro-spikes which I use with Altra trail runners for general trail snow/slope use. They even work well for the major JMT passes since the approaches are usually at an angle to the mountain.
However, for something like Whitney, where you have to go straight up ie facing the mountain directly, either via the Chute on the main trail, or the gully/final 400 on the MR, you need the real deal. By that, I mean a light mountaineering boot with a semi/quarter length shank, and traditional, front teeth crampons like the BD Contact. Remember that you aren't going to be following footsteps, but rather will be kicking in to gain purchase every step of the way. That's where the shank comes in, since it transfers the rigidity from your toes/foot bones to the sole.
It's a bit of an extra investment - say $500 or so - for such a specialty piece of equipment, but IMO it's worth the cost. Besides, the same boots can traverse a lot of snow fields with just the square sole vs trail runners with spikes. By way of example, I can move pretty effectively from LP lake all the way to Trail camp without traction.
To be safe and have fun in challenging conditions - look at the photos of people who have accomplished such an awesome goal, the exhilaration is painted on their faces - instead of being terrified and perhaps being injured or worse (happens every year), it's worth the money. Consider that a good pair of boots like the La Sportiva Trango Cube can last a lifetime of use. Besides, many boots/crampons are on sale right now (winter is over for the majority of the world):
https://www.google.com/search?source=hp&...i30.qkAFiA7GHLEhttps://www.google.com/search?source=hp&...i30.A6uAP0kTNEEEdit: I think this photo perfectly captures gear, technique and style. Go equipped like this, and you should have the time of your life.
