The rules have changed Frank. The ABAA system no longer exists, it's all experimental now and there are no stage inspections or certiication required in GA except for the final issue of the C of A.
In the RAA world you can build under CAO 95.10 amateur built, or LSA experimental. You can buy factory built CAO 95.55 etc or LSA and only factory built aircraft can be used for training, except for to the builder of a kit built aircraft.
LSA kits must comply with the LSA regulations and be manufactured after a certain date (around 2005).
LSA can be either GA or RAA registered as factory built.
What I don't know is if you can register an LSA under experimental GA however there would be little point anyway as you may as well go GA experimental.
When you make a full comparison you will realize that GA experimental is quicker and easier with less paperwork hat RAA and if you have co-owners they can also learn to fly under GA but not RAA and of course under both registrations you van perform owner maintenance.
The primary reason why RAA builders would build under LSA would be to take advantage of the greater 600kg MTOW, other than that there are few if any benefits.
It's ironic because LSA was invented to level the GA vs RAA playing field and to bring in new lower cost GA aircraft to help the GA schools compete with their RAA counterparts for cheaper flying training. A good example of this in practice would be the LSA registered Sportstars that you yourself Sunfish fly at the RVAC.