Does anyone know of any high-level players that use tatacons instead of keyboard?? I'm wondering if I should learn taiko using a tatacon instead of keyboard (and if it'd be more fun that way)
You may use the TaTaCon drum if you want, but it will be harder to play (keyboard-friendly patterns and streams), but you can practice them at special thread named TBT (osu! > Gameplay & Rankings > osu!taiko > see pinned threads).
I know that OnosakiHito also has a Tatacon (or similar drum controller) and is fairely good, but he's also a keyboard main when it comes to playing, so not sure if he actually counts.
I myself also use a tatacon now and then, but I'm not exactly good (Oni is my limit there).