My experience recently is that hotspots give much more xp than LDoNs.
Since LDoNs scale to the avg level of the group the lower level members get more noticeable xp, while the higher level members often complain about getting almost no xp. Only if the group is all within a couple levels and you go for a Hard mission will the xp be what most people these days would consider decent. However, hard LDoNs can be challenging if you don't have the right group.
Some hotspots are train-prone, some are challenging for other reasons (key required, zone out not near zone in, things like that) but they all have new named dropping new inflated gear, and all have those unmasked changeling mobs that drop augs better than any LDoN aug available near the level of the zone.
Spells from LDoN merchants are now tradeable, with the notable exception of Remove Greater Curse. Many of these spells are also researchable now too.
I love LDoNs and wish I could do them more often. As it is, I have to work very hard to put together a group willing to do one when I really get the hankering. Almost no one wants to bother with them when the xp isn't so good anymore. Cheers for making most spells tradeable, but they also need to either reduce the point cost of items, increase vastly the amount of points rewarded, or change LDoNs to allow adding or replacing members after the adventure is given.