I’ve flown the 175 extensively and also fly the 139. In my opinion the 175 wins hands down in the way it flies! The 139 is a very capable machine but it is old technology and shakes its self to pieces. The 175 has had a difficult birth due to Airbuses reputation but if you want speed, power and comfort then the 175 is my choice. I’m sure the 139 crowd will disagree.