This whole thing is a veritable treasure trove, I tell you. :P I've been playing Twin Snakes for so long that I had almost forgotten what the old voices of Mantis and Ninja were like. IMHO, the new ones are a lot more sinister, which fits well for their positions in the game (Mantis as an evil boss man, and Ninja as a kickass soldier-slaughterer), but I'd almost forgotten that Mantis was Russian!

Quite a few of Liquid's lines seem to be left out, as well.
TBH, in the end I'll probably end up using a mixture of sounds from original and TS. Still, this is a TREMENDOUS help.