Hippo did a great summary. I started out with a sportster, traded it to a heritage soft tail classic (which eventually went to my wife) and we added a road king classic to the fleet.
After a season on the king, we traded the heritage, kept the king and I bought a "lightly used", fully loaded electra glide classic.
Couple of things:
1) really glad we were in a position to rationalize keeping the king - it is an amazing bike, and I get a real rush every time I take it out. I should add that it is pretty loaded, so works well for our numerous distance runs - we added a tour pak, stage 1, pipes, and touches of chrome that have people looking and talking EVERYWHERE we go.
2) the previous owner of the glide added pipes, stage 1, power commander, cruise, lowers, detachable kit to the tour pak and bags and a lot of chrome, I added rear speakers, a 70 watt upgrade kit and upgraded the front speakers. Over the winter I'm upgrading the stereo system to handle cb and cd - whoever says the glides can't be dressed up is wrong - I think it just takes more bucks to get them to show off. However, it's fair to say that the KIng looks the part when it's decked out.
3) between the two bikes, if I'm taking a short hop or going into town, I will take the King. As soon as I'm running the highway, going on a longer trip etc., I'm on the Glide. They are both more than capable of either task, but the e. glide is definitely a more comfortable bike on the highway, and I enjoy the added comfort and protection it affords.
4) If the e. glide hadn't had all of the work done on it that it has, I would have gone to an ultra.
Being able to keep your first ride gives you a great opportunity to go for the biggest bagger you can afford.
Enjoy! And ride safe.