Why does the shape of the handle matter? The handle is where your weight rests on the cane -- a well-made cane for support is made to guide that weight directly over the shaft, where the cane is strongest. A more casual user might like the look of a tourist cane hanging on an arm when not in use. A person with MS might need a cane for sturdy support. It may take trying out different handles to see which one meets your needs. I personally use a Palm Grip handled cane, as I have arthritis in my hands and have to lean hard on it.
I have arthritis, carpal tunnel syndrome, weak grip, etc. -- which handle is best for me? The Fritz handle was created for just this purpose, but there are other comfortable handles for achey hands -- foam-padded, soft touch, leather covered, contours or palm grip -- the shape and the material together can make a very comfortable handle. You may find you need to change your handle preference over time.
Which is better -- a wood cane or an aluminum one? Several questions have to be answered first, as in -- how do you wish to use this cane? Everyday? For travel? Dressy occasions only? Serious support? For instance, a high percentage of travel folding canes are made from aluminum. Half of Big and Tall canes are solid wood. Finding what your need is, is first, and your specific preferences are second; then we can figure out what meets both the best.