I had a 2000 Monster 900i.e.
Very fun. Technically pretty neat. Fuel injected, desmo valve system. Nicely made bike, I never had any problems with it.
I've had lots of other sports bikes, mostly high revving japanese bikes. The Duc was more like a V8. Two big cylinders = lots of torque. It was fun to cruise at 3000 rpm and roll back the throttle and feel the torque. In my old age, I've come to like torque more than screaming revs.
The sound was also awesome with the carbon pipes and an open airbox.
To my eyes, it was absolutely beautiful to look at. To me, perfect, just how a motorcycle should look and feel.
I think mechanically, the 900SS is similar.
Fun bikes, I liked it a lot.