From what little I've seen of the term, it appears to be a fancy name for a technician. In other words, an engineer designs things, the technologist installs/builds/integrates them.
If they really are not more than glorified technicians, they probably don't make as much as an engineer. However, they don't need to go into debt for school like an engineer would either. If you enjoy working with your hands and getting closer to the real work, then a technologist job may be right for you. But the promotion opportunities probably aren't as good. Frankly, I don't know why this should be, but it is what it is.