Oh my. This is a subtle, esoteric compressor if there ever was one, but it remains one of a handful of freeware plug-ins I can't believe is free.
If you're not familiar with feedback compression, or if you're indifferent to compression's inner workings such as the particulars of envelope curvature, side-chain filtering, oversampled control signals to catch intersample peaks, et cetera, this might be an easy compressor to overlook.
The comprehensive control scheme allowing to meter off a crest factor rather than merely peak or RMS, and the ability to set different release controls varying on peak vs RMS, makes this compressor unbeatable for more complex signals higher up in the buses of the mix. Or dynamic, polyphonic instrument tracks.
Add to that a built-in adjustable high-pass filter to the side-chain (makes for a cleaner sound on bass-heavy buses with a slight roll-off, or when cranked it allows it to double as a remarkable de-esser on top of being such a great vocal compressor already), adjustable stereo sensitivity rather than simply choosing between stereo/mono - this is a compressor designed for and by professionals.
I think the problem you gave a great product a bad review based on some assumptions. TDR is a digital and transparent compressor while presswerk is an analogue model - they are designed to achieve different dynamic action and you based your opinion on CPU load not the (outstanding) quality of the product.
Ok so 30 intances of Kotelnikov (eco mode) in Studio one 3 is hitting 30/33% CPU and 30 instances of presswerk about 15%. My Macbook is 5 years old so its not the latest by any means. Kotelnikov is specified as a mastering or bus compressor. It is not designed to be on every track. your review was not conducted with any level of respect towards the purpose of Kotelnokov - it is totally worth the CPU 'hit' how about you do a review based on the sound / features and ignore the CPU hit giving 5 out of 10 based on CPU is disingenuous. I mean if you could run 1000's of intances of a poorly implemented compressor would you mark that higher?
CPU is certainly far less relevant then it used to be - the amount of power in most pc's, Mac's etc is more then sufficient for production tasks. I don't want to do reviews so thats why i don't but giving poor scores, while leaving out important info (i.e. comparing a track comp to a mastering one) is harmful to developers and I felt your review was unfair.
Also if the plugin's CPU cost was not related to output quality then I would agree but it is not a coding issue it is a design choice - read the manual it explains it all there.