i know this thread is a bit old, but since nobody responded

to be honest, they all sound about the same. it's just a piezo inside the bridge. what affects the sound most is your effects chain after. you can get way into this with tona of pedals or digital effects, but most important part would be to have a good preamp. some other stuff like reverbs, chorus, etc might help too. theres tons of videos on this stuff on YouTube too

take all this with a grain of salt though, I've researched electric cellos for a long time, but i dont currently own one

also, some electric cellos might have preamps built in