Down Mixer Plug In VS Neyrinck Soundcode LtRt

Can someone tell me what the specific difference is between the Pro Tools Down Mixer plug in and Neyrincks Soundcode LtRt. Is it Neyrinck's ability to encode Pro Logic into the LtRt file and will it be embedded if you bounce to disk an interleaved stereo file? Can you also do it by bouncing a Quicktime movie out of Pro Tools?



cheers