What I think you have been exposed to, is the old style of subdivision, at least here in Queedsland. They used to be broken down to
a. Stand alone block. RP, which stood for Registered Plan
b. Villa or Townhouse. Again, which stood on its own land, however enjoyed the use of some "common property". GTP, which stood for Group Title Plan.
c. Unit. In a block, and generally they were off the ground, with a garage or another unit below, ie the "air was subdivided". BUP, which stood for Building Units Plan.
A few years ago, they went to a standard SP, for all types of subdivision, which I believe stands for "Survey Plan".
Not sure whay any one would try to say one form of title is better that another, as they are in my opinion, much os a muchness. In b and c, you are part of a Body Corporate, whic you will not be in a.
Hope that helps