I used to own a argentine boa long ago and yes their mean but they can be tamed. After enough effort he turned out to be pretty handable i regret selling him. Now considering you wanted something calmer with all do respect to everyone else i don't think a argentine is the way to go.lol Though if you want an interesting sub species and can put up with it then go for it but i'll just recommend a boa. You got more variety with boa's with a dumeril you're probably gonna end up with just a dumeril. Also don't get me wrong dumerils are great just i think boa's are better overall.