I was talking about the 6th full-frequency channel, as in the rear back one. It is discrete indeed. There are two, DTS-ES 6.1 discrete and DTS-ES Matrix. It is right on the DTS website, and here in more detail. The matrixed channel is always present in the Ls and Rs, but in the case of 6.1 there is also a discrete back, and with a DTS-ES 6.1 discrete decoder you can play that discrete channel, and subtract the already redundant matrixed channel from the Ls and Rs. Dolby Digital EX is the one that is only matrixed.
But about the non-discrete LFE channel on DTS:
You missed this tidbit right after what you quoted (which incidentally also says the same thing)
First sentence is correct (without the "therefore"), but second sentence is not, from my experience with DTS-ES discrete movies and my 6.1 speaker system.
Its right what you say with the discrete version, but I still doubt that PDVD7 can decode more than 6 channels, they (CL) even told me several times they don't. I think they just mix a virtual 7th channel as it is simply impossible with the existing decoder of PDVD7 to decode discrete 7 channels.
But I think we will never have proove about that issue so lets just go along with PDVD8, PDVD7 (unfortunately->HD-DVD) will be history very soon...