I watched, and listened to some of the Youtube video presentations of the Slate VTM.
What I heard was very subtle, barely noticeable. I guess some users of Tape Saturation plug-ins seem to like the effect, but it did not make me go WOW ! now it sounds like a 2" tape recording
Using high-quality EQ and Compression Plug-Ins, and sending your mix OTB to a quality (outboard) Pre-Amp and Compressor does a lot to improve the warmth/analog factor, plus the overall depth, and width of a stereo mix. You can hear it right away ! and even say … WOW What a difference !