IMHO ISO files are an anachronism: They aren't terribly useful. Unless you really, really love DVD menus. I say rip them all to MKVs and never look back. Bye bye encryption, bye bye slow menus, bye bye forced trailers, forced intros, etc. Bye bye to all slow downs. Now I just have the movie, which plays instantly on nearly any player. Bonus: MakeMKV reads ISO files directly and rips them rather quickly.
Thus ends today's (digital) sermon.
Brian.
I still like ISO files.
They're a single file instead of a folder with many files.
You have a copy of everything on the disc.
With the movies I converted to MKV, I had to re-rip the discs again when 3D support was added.
I usually only rip the english audio and subtitles. That's fine for me but then I had guests over who wanted non-english subtitles.
You have to work out what is the correct title on the disc and which of the subtitle files are required - if any of them are forced because a part of a movie is non-english - at the point of ripping. With ISO you put the disc in and go.
I've started ripping to MKV only after I've watched a movie now because of that, and it were not for space, I would just be storing ISOs. (MKV allows you to store about 1/2 to 1/3 more movies if you're cutting out multiple languages, converting audio to FLAC)