This is very nearly a legacy connection, however, which means
that it is becoming increasingly rare to find this on new power supplies, and is it
also becoming difficult to find adapters for this kind of connection.
You can buy all sorts of different LEGO sets
out there, but in my opinion this particular set IS the Ultimate
set that everyone who plays with lego should have.
Growth is when you take new things that you dig up and discover, and
integrate them with the rest of who you already are.