In the Propellerhead shop it says as of Jan 2019 "The Rack Extension version of Bitspeek is more advanced than the current AU/VST counterpart. Improved volume tracking algorithm with much better transient response and consistency across source material and sample-rates. ".

Is that correct or did the latest VST version (1.5?) get the same update?

Sorry, that is not correct. Version 1.5 of the VST includes the same volume tracking algorithm as in the RE and also stereo input and output. The original algorithm is still available in the VST as "legacy mode".

The RE offers plenty of inputs and outputs not available on the VST. That is the only major difference now.

I have updated the RE page (waiting for approval). Thanks for observing this.