How is the "Depth" knob different from the "Dry/Wet" on the Ableton OTT?

I usually use the Ableton OTT, but I saw that there a some different options on the xfer OTT so I thought I'd grab out of curiosity.
I'm a bit confused though, how is the depth different from the D/W on the ableton ott?
I came across another thread on here where Steve explained it a bit, saying something a D/W knob is basically parallel MB compression, which is no good on the master. 
At 0% and 100% depth or dry/wet, both OTTs seem to produce the same effect, but anywhere in between is in theory different since on ableton OTT 1-99% d/w is parallel but this is not true for the xfer ott?
I'd like to experiment with OTT on the master, but after reading the other thread and watching the razer video, it seems that using the xfer ott for mastering is the way to go. So I understand that, but I'm curious as to how "depth" is functionally different from d/w?

I don't recall what Ableton does (you can try to research that yourself, e.g. if scaling back wet lowers the compressor GR on the metering).  

Depth in my VST scales all 6 dynamics ratios from whatever to 1:1 (effectively bypassing the compressors).

Thanks for the explanation! You da man