Hi Arne,
Thanks for the hint. But we also encounter CPU spikes when adjusting a knob in case of explicitly using CALayers. So, not only our meters are affected. But with meters, it is constantly bad. So, basically every kind of animation is a potential problem. But we will try wrapping control bundles into Layered View Containers.
Thanks again to Arne and Ray for the input. We will investigate soon and consider your suggestions.
Regards,
Joscha