I've kept a number of Salvini's, Normal blue Acara and EBA over the years. Only really had problems twice, a small Salvini that proceeded to tear up the fins of any similar sized cichlid that was introduced to the tank after it, and an EBA that appeared to be quite calm but if you watched closely was a vicious little thing that randomly bit tankmates that were not watching. I introduced a school of 6 rainbowfish with this EBA and it picked them off one after the other over about 2 weeks. They were quite big as well. Generally though all 3 of the types above are OK, Salvini usually not as bad as they're made out to be, they actually hide out of the way most of the time, its really down to individual fish. None of them usually get anything close to the maximum size quoted either, they normally all get to 4 - 4.5" in the main.