A couple of points...

DTS-HD Master Audio Suite costs £1,000
Dolby Media Producer costs £7,000
DTS-HD Master Audio Suite is Mac / PC
Dolby Media Producer is Mac Only
All Professional Blu-ray Authoring Software is PC Only
Both Dolby TruHD and DTS-HD MA as lossless codecs, which compact the data more efficiently like a zip file.
Because they are lossless they are VBR encodes, like video and only peak when required.
DTS-HD has legacy DTS 'core' which is automatically decoded if the end user doesn't support DTS-HD MA.
Dolby TruHD is two files - a .mlp and an ac3 file.
Although 2 separate files, they are married on the disc into 1 stream, which then works like DTS-HD allegedly. I've never done it, and I remember The Dark Knight defaulting to the lossy dolby ac3 file.
I believe there used to be issues with Dolby TruHD and ScenaristBD authoring. These have all been fixed now, but of course in the early days when everyone is making purchasing / house style decisions, it was a factor. Looking back through emails, I can't find the specifics at present.

I don't give a flying wookie what a disc has on it, but as far as I'm aware what was shown in a cinema bears no relation to what is put on a home entertainment disc.

Don't forget that most titles get a different 'home entertainment' mix because the speaker configuration, size and distance is different to a multiplex.

And do you know what they do once the mix is completed? They save out files (Broadcast Wavs, ProTools Sessions) or they lay the audio off to a DA-98 TASCAM tape, or if they want to put it with video, perhaps an HDCAM SR. And then when the authoring house receives it, they capture it via SDI / AES.

Dolby and DTS are delivery products.