The biggest differences in how an antenna is loaded amounts to being practical. What's the most efficient that you can manage.
I think you will find that the continuously loaded type antennas are the most common, followed by the base loaded ones, then the center loaded ones and then the top loaded ones. Top loaded antennas are not very common for a good reason, even if they are the most efficient. For practical purposes, this is almost the exact opposite of how they rank in usability for the average person.
The continuously loaded, helically wound antennas are the -least- efficient! Sorry, but that's a fact. That deals with the efficiency of coils in general, specifically with their 'size' and 'shape'.
Top loaded antennas are the most difficult to make practical for several reasons. I'll bet you can figure those reasons out for your self.
Center loaded antennas are probably the 'best' compromise in practicality and efficiency.
Base loaded antennas are the most common, the most 'practical' for the average person, and are not all -that- bad to start with. They can take much more 'abuse' than the other kinds of antennas.
While there definitely is a difference in efficiency between all these kinds of antennas, in general, that difference isn't going to amount to much at all.
If these different antennas are of a comparable size/length, their effectiveness is going to also be comparable (radiation pattern). So, at least for me, the deciding factor is just how practical the thing is going to be for me. How long will it 'live' in the use I put it to. That typically means a base or center loaded antenna. Does that mean I'll have the most efficient antenna possible? Nope, but then, I don't expect 'perfection' very much. 'Good enough' works!
- 'Doc