i dont know if playing both would be a good idea. i have tried etterna and id say my acc on there is alot worse than mania on both 4k and 6k mostly because of how accuracy is handled and differences in charts. im thinking playing both is a good idea since etterna could be for developing accuracy and osu mania for playing faster but i dont kmow if thats a good idea and if i should stick solely to etterna/mania. if anyone hhere has tried etterna please leave yoour thoughts