I first heard about virtual drummers from a friend who uses Drummer in Logic Pro. Since I'm on Windows 11 now I started searching for alternatives and came across Jamstix and then EZ Drummer 3. From my intelligence gathering it would seem that both alternatives leave Drummer in the dust.
After investigating each alternative with whatever means available (manuals, videos, demos) I've come to the conclusion that Jamstix has EZ Drummer 3 beat by a good distance.
EZ Drummer 3 has the new Bandmate feature, which under the hood is still just a way to infer data that is then used as criteria to lookup rhythm patterns. After all, tons of premade patterns are still the basic essence of what EZ Drummer 3 offers. So Bandmate just makes use of an audio API to derive dynamic transients that are in turn used to perform a search and return pattern suggestions from a library of premade patterns.
Jamstix in contrast provides an editor to model the sections (parts) of a song. Each part then has its style and drummer rules used to generate rhythm patterns on-the-fly. This approach leads to a much better result that fits the music better while also letting the drums have their own voice, instead of having them completely shadow a guitar audio source for example.
The drag in a audio file/part and then generate (not just match up to existing patterns) a pattern of drums would still be a cool feature for Jamstix to have. As far as I can tell Jamstix does have a audio jamming feature but the data inferred from the audio is used to influence the drums being generated vs completely generating them.
These are my thoughts after some consideration on what product I want to use.