Hi, I had Silverfast with my old scanner. Both versions work almost the same.
It's just a different interface. You are able to use both in PS. The difference is that TWAIN was supported by more programs (even some wordprocessors I think, simple graphic programs, etc) than PS plugins. It can be a boon when you just want to scan a bunch of slides without having to run photoshop, you just execute a small launcher utility which calls the TWAIN function and launches SilverFast. And you can still launch it in Photoshop trough PS's TWAIN call. However, it's possible that both versions differ somehow. IIRC in the old versions the PS plugin had better support for saving 48-bit (16-bit per channer) images. But that was about 5 years ago... Incidentally, in Photoshop, both versions install into the File/Import menu... You can't tell which is which until you launch it! fra

