I've removed over a gig of unnecessary files (may have gained a few fps, game isnt' as choppy as before).
Haven't started a new campaign, but if anyone's interested here are the files I removed-
1. Sound files- lot's of useless stuff, pick and choose what you want to delete (or add, I used some from SH3). Also deleted radio and gramaphone wavs/ogg since I have old radio tunes burned on CD.
2. Redwine's "Increased Underwater Visibility" mod. Apparently a shading issue, but game seems to run better.
3. Intro/campaign/single mission Movie files- kept the folder and any configuration files. Game hasn't crashed yet (keep backups just in case).
Go to your Ubisoft/SH4 file and click properties, then compare the file sizes to those in SH3.
Yours, Mike