Well for me it was the ability to have looped envelopes for some automations and at the same time MIDI control for improvising with other parameters, it helped create variations of the same mouvements, with one impro you could make quite a few one shot sounds that would feel like they belong together and still have some differences, like words from the same foreign language…
And I like how you could synchronise stuff easily too, and the global sound it had. Oh And you could use VSTs inside it and control their parameters the same way…