I only just realized that I have Ultima 4 in my library twice, once bought ages ago by itself, and one recently as part of a trilogy set; does it matter which release I play? Does one run better than the other, or anything along those lines?

I was just about to ask this. Is it actually the same? The file sizes seem to be different. One is 11mb and the other is 13mb.

I just downloaded both as a test. The file names are the exact same, but the sizes are indeed different. Not sure why.

As far as the Offline Installers are concerned, it appears to be the same version (as you can see by the (1) on the 2nd file downloaded to the same location.

(Disclaimer: I had to rename it and put back the (1), since I removed the (1) when I moved it to another location, before realizing the whole purpose was to compare them lol. But originally, it was exactly as shown in the png file here.)

The only thing I can think of is that maybe the larger one for whatever reason, includes maybe one or more of the files that we find in the extras section. I did notice Lorebooks is missing in the free version (included in the paid version) in the Extras section.

Ofc, this is pure speculation on my part. :)

Here's a screenshot.
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Update:
- I just went back and checked and Lorebooks is 38 MB in the Extras section of the paid version. So I don't think that's it lol.
- Guess installing each seperately is the only way to know why they are different.
- Unless it's just better compressed in the paid version. Oh well, I tried haha.
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I'm wondering the same thing.

The actual Ultima 4 game files are the exact same.
Differences in folder name it installs to.... and some GoG specific files, nothing that changes the game itself.
Did not check the Extras that can be downloaded. But can get those anywhere.