I tried a new pair of stiff souled mountaineering boots on the Manker Flats trail recently and paid for it. The trail is just too dry to justify stiff souled boots. For me on that trail, trail runners and microspikes are the way to go.
As Greenmountainboy mentioned, there are very few places where you will need them, mostly between 8,200 feet and 9,000 feet. You will probably need them in the rock garden just beyond the ski hut and will need them through the forested area above the rock garden, but after about 9,000 feet, the need for spikes will be few and brief.
Brent N