from my personal experience with both many different types of outboard compressors and every dynamic plug in known to man...
I don't think t racks is setting out to replace outboard opto compressors and fairchilds, however, this is some of the strongest dynamic processing I've ever heard in plug-in form. Excluding some of the UAD stuff. I used to avoid heavy compression with plug ins until this.
Specifically
the linear phase EQ, fairchild, brickwall limiter and opto compressor. You can tell that from the type of clarity you retain, even in super high compression settings. Super transparent if you really listen for it. Pretty smooth all around. That's what got my initial reaction.
The opto works really well on stuff that need to stay clean. Vocals, guitars, kick and snares, bass, etc. It reminds a little of
the DBX 162 series of compressors.
The pultec EQ is good, but not really the type of soul I remember hearing on any of the pultecs I've used. It just sucks on CPU usage cause of the oversampling.
The fairchild gets a little dirty with high compression, but sounds rock solid on alot of buss compression stuff that dosn't need super high end crisp. It dampens stuff up a little.
I'd treat it more as just a really good plug-in set than a copy of the originals.