It was the "Superman and the Legion" story in ACTION not long ago. It's been collected. Wherein Geoff Johns manages to have two sequences that, yeah, are about Clark's friendship with the Legion, but also are about how everyone remembers their childhood friendships and what they give us. Johns, I think, is at his very best when he's writing about Clark, because he understands (like Morrison) that Superman's true appeal is in being an odd sort of Everyman, that Superman's story is how we feel inside, writ large. This is the second of those sequences: http://asylums.insanejournal.com/scans_daily/710493.html
It's not too easy to write about something NICE and make it interesting, and to be sentimental without making you barf. Gary Frank's art helps a lot in that.
As far as this Legion and continuity--why? They're in the future. What Johns did was simply say that they hadn't been written about in a while, that's all. So he went back to them. No retcon, no reboot, nothing necessary, one just picks up where it left off, which fortunately wasn't too bad a place, and already well-developed. He just needs to explain why Superman forgot them and it's done. But I think that was explained as the Trapper's doing.
The Levitz/Giffen Legion was already becoming transitional to a more mature kind of DC comic--nowadays it would almost look innocent by comparison to the rest of the line. But back then, it was a book that was serious on the drama. People COULD die. Worlds COULD be destroyed, even universes. You knew, reading it, that it would not be a static book one month to the next. That was, I think, why it was appealing. And it was, being Giffen, like OMEGA MEN heavy on the guck. I remember the issue when we found the real nature of the Durlans, when we saw their devastated world, and the constantly-shifting formless bodies they really have(as opposed to the Orange Spock one they wear for the benefit of others) and the nature of their combat. That stuck with me. For the first time I understood why Durlans give people in the 30th/31st century the creeps.
To be perfectly honest, though, I didn't care for the other two Legions. The first, well, it just wasn't done for me anyway, it was for kids at the time ten years younger than me. As for the more recent Waid version, it seemed too smugly CW-ready for my taste and the youth-against-age thing seemed very silly. Two things I did like: when Brainy casually cut off Cham's hand, and the unique relationship problems of Tinya, which seemed like the worst asshole-who-won't-stay-off-her-cellphone situation I can imagine.