True Sorcery & the True20 'magic' system: compatibility?

[Akrasia]

Is the magic system in 'True Sorcery' meant to replace the (default) True20 'magic' system? Or is it meant to be a system that is distinct from --but compatible with -- the default system (something like the way in which psionics are 'distinct but compatible' with standard D&D magic)?

Thanks!

[Akrasia]

Er ... sorry for not posting this query in the 'True Sorcery' thread that I started a few weeks ago. I've had a few too many Beamish this evening...