Apistos can be mean but they can also make nice community fish ime. Depends on the individual. I know a lot of people have angels in a community and some have aggressive angels. I've never heard of an angel being extremely aggressive (like a jag or red devil tends to be). I think people who classify angels as really aggressive haven't dealt with cichlids that are truly extremely aggressive. The angel in my tank fits right in with my other mellow cichlids (nics, chocolates, cutteri, rainbow, sev). From his previous owner, he is evil towards other angels so I just won't add another angel to the tank.
I have also had aggressive rams. Chocolates are definitely pretty mellow, but I left them off the list since they will also eat any fish that fits into their big mouths and the OP didn't say what size tank they're working with. I guess you could add discus to the peaceful list too.