I wouldn't touch any bike that uses a Brose motor.
I've read too many concerns in respect of weird power delivery, and iffy software.
For my use, the battery pack is also a very questionable aspect of the Bulls/Rotwild bikes, and that again, has put me right off.
I did investigate buying a Rotwild, but the above and also a forum member cancelling his order because of concerns about the Brose motor, was more than enough to put me off ever wanting one. I also privately and publically requested a demo bike to format my own conclusion, but no response was received. That again, raised concern with me.
I'll stick with Bosch powered bikes, as whilst they are not without fault, I know exactly what I am getting, and what can be expected. from both the product and the superb support.