Back in 2001 I saw those on a Super Connie they had at Camarillo Airport. Note that it had three turbines.
I saw a video in which a former Lufthansa pilot described the Super Connie as "A three engined airplane with four engines" which gives you some indication of the engine's reliability. A friend of mine served on EC-121 crews that flew out of McDill AFB and did radar surveillance to see if there was traffic between Cuba and Nicaragua. They would shut down the two outer engines to extend their mission time.