What I generally donīt like about ALL subsims Iīve played so far is that the speech-files always sound sterile and not at all enthusiastic, emotional or tense or immersive. Just compare the way orders are spoken in "Das Boot" to that strange, clean style of SH3. Besides, most orders are historically and/or technically wrong, at least in the German version, my favorite "anti-speech-file" is this ridiculous "Derzeitige Tiefe x metres" ("current depth x metres") or "Normal Tauchen" (which literally translates "ordinary diving" - thatīs a bad joke, really!
I replaced most of my files with "Das Boot" ones.
My two cents,
AS