Some guys say that Sparky is too fully of all the applications and other things. They prefer base system only to configure everything themselves.
Other some guys say that the base edition is too pure and they'd like to see more equipment preinstalled.
That's why a few editions are a larger set of tools and some less.
And a one more reason is: I compile e19 myself and I always test many times the compilation on hard drive, deb packages installed on virtual machine and new iso images with the new compilations. Bigger iso means longer time for me, but it is limited. So I prefer to make e19 spin smaller.
Is there a simple way to install all the codecs at once
No, there is not, install theme via apt or Synaptic.
Anyway it's good question and I will make an option to install all the codecs via one click in APTus and APTus-Extra.
would I be better off (codecs wise) installing that then upgrading?
It's your choice.
If you'd like to upgrade, follow the upgrade info:http://sparkylinux.org/sparkylinux-3-5-1-e19/