No oscillator modelling, but you can use samples plus filters and modulation. Since it has a reasonable amount of RAM, you can get good granularity in terms of say - a sample (or stack of samples, which can cycle per trigger) per note value.
So, it’s reasonably powerful. Couple it with a good analogue modelling multi-timbral synth, like say a Virus Ti, and you have a lot of coverage.
I do find the key-group setup a bit un-intuitive. Key-groups are the mechanism for loading samples to be played back per MIDI note. I’d normally rather hook up to an external synth for melodic stuff, rather than use key-groups.
I prefer the sequencer to Elektron’s, especially the ability to use more than 4 bars without having to resort to chains or tempo trickery. I just hope that Akai continue to make incremental improvements.