One thing I was always confused about in realMyst: The message Sirrus left on the imager in Channelwood is totally different to the one in Myst.
It seems to be a different take of what is basically the same dialogue (which I won't write out, since this is a non-spoiler forum). But in my opinion, it's not as good a performance. The dialogue is rushed, some parts are skipped, he seems less like he's acting and more like he's reading the lines. Also the overall video quality seems much worse. I've always wondered why they decided to use this alternative take in realMyst, when every single other Sirrus/Achenar video is straight out of Myst.
I'm kind of hoping they'll go back to the original take in realMyst: Masterpiece Edition. In general, I'm wondering how they'll deal with the Sirrus/Achenar footage. There's been some discussion on this forum about whether Cyan has the original recordings -- it would be exceedingly cool if they could go back to the original source material, clean it up and present it in high resolution. If not, well it looks like the realMyst videos seem to be taken out of Myst, and re-compressed with some bad 1990s codec, so they are double-compressed. Hopefully at least they will go back to the original Myst videos and convert them into a good modern video format that's hardly lossy.