Teleport vs Long Range Teleport
Normal teleport allows you to teleport to X-distance in your line of sight while LRT is, as you said, a special train stop. It allows you to travel to any zone of your morality.
Can it be used inside an instance?
haven't tested this for myself, but I think so since use of the power brings up a zone selection menu similar to the Base Portal and the Market Teleporter,which do work inside instances.
long range tp is also depending on where your at too, if your in a heroside zone you get a box with heroside zones, villainside-villain zones, praetoria-praetorian zones

Does this work in/for the Shard? Can I TP into the Shard, or am I still limited to the long walk out there and a fast return?
Life is pleasant. Death is peaceful. It's the transition that's troublesome.
Isaac Asimov
You cannot teleport to the Shadow Shard/Firebase Zulu. In addition, it should be noted that not ALL hero zones can be selected as destinations (something which many of us feel should be fixed). You cannot access any Hazard Zones.
I think Peregrine Island might also be inaccessible, but I am not sure and am at work currently, so I cannot check.
@Winter. Because I'm Winter. Period.

I am a blaster first, and an alt-oholic second.

That's not so bad. The Shard isn't terribly popular anyways. Where does the TP drop you? the Oro zone-in point?
Life is pleasant. Death is peaceful. It's the transition that's troublesome.
Isaac Asimov
It drops off in the train station for a zone. I believe p i was on my list of hero destinations. If you choose the zone you are in, it will drop you at the tram, a nice feature in places like those islands the circle like in talos, to get back to train up or go to ww.
The final line of a post by Sweet_Sarah on Liberty
"Together we entered a city of strangers, we made it a city of friends, and we leave it a City of Heroes."

Can someone with experience explain the difference to me.
The way I would assume LRT works from the description is as a longer range version of TP.
But I could easily see it as a special train stop for TP users.
How wrong am I?
Life is pleasant. Death is peaceful. It's the transition that's troublesome.
Isaac Asimov