Probably not really the answer you are looking for, but here is why we use a core aerator instead of a spiker (we started with spike)
My wife runs a lawncare and landscaping business, People want their yard aerated. We provide that service, when folks come home and we have spiked it, they do not see that we did anything, if they got on their hands and knees and look closely, they could see, but the folks having this done, are not usually this type of person.
However, when we switched to the Core aerator, it pulls up and leaves little worm droppings all over the place, the customer comes home and see's that something happened and is generally much happier.
Not to mention, imho, you are actually doing more to aerate and break up the soil.