I'm currently using Harley Davidson Superlow. Is it good to go for Ducati or Triumph cruisers?

I think Thunderbird Storm would be best answer for satisfying your quest for Cruiser bikes. This is a 1699 cc bike with a six speed gearbox capable to produce 98 PS at 5200 rpm against a torque of 156 Nm at 2950 rpm. The bike has a dry weight of 308 kg and fuel tank capacity of 22 litres. With a wheelbase of 1615 mm and seat height of 700 mm, this cruiser bike offers you one of the most comfortable rides.