Firstly, I hated them because recently I've used an original session Virus Demo to preserve some settings and forgotten totally that session was 16 bit. I've made two session of it until I realized that sound was duller that ever before. (Try to find out in any session in what format that session is, huh!? But what I saw in PT 5.1 demo video, the problem is all ready solved.)
Than I've tried to import one of 24 bit sound... You know the rest. I was spewing!
One session I've rerecorded, (Waste of 6 hours solid work.) but yesterday I was backing up some the most imported stuff on another hdd and I was trying to save Copy of Session and than I've noticed that format could be 24 bit! I went for it and… bingo! All files were converted to 24 bit and IMHO session sounds better now for sure.
I love Digi again.