The only one of those 3 sportsters worth buying would be the 94 1200 model. The other 2 wouldn't be worth trading what you currently have for them.
Sportsters are fucking tanks of a bike. There's very little with them to go wrong and it's still using the same basic engine for ~30 years now. You really need to ride one though to tell if you'll like it or not. Sportsters carry their weight really high up and feel top heavy. Some people can't stand that.
I don't know what the one poster is smoking but with a sportster you'll be operating at a pretty low cost as well. Nothing you can't do yourself really.
the 89 and 94 are "rigid mount" bikes where the motor is mounted directly to the frame. They have the best lean angles of all the sportsters and are some of the lightest bikes. The downside being that the aftermarket support for the rigid mount bikes isn't nearly as numerous as the later generations.
The 04 is a "rubber mount" bike but is the first of only 3 years to have a carburetor. It'll be heavier, have rubber motor mounts which need to be replaced as a wear item, but is somewhat smoother. I say somewhat because it's not really all that much smoother to be honest. Sportsters are "buzzy" bikes in the sense that they just vibrate.