Peter and I did part of the new chain. Like Eveningstar, it is several flagging quests with a final afterwards, and a chain giver. We did not do them in order.
The High Road explorer is much like the King's Forest, except not as excessively huge. We managed 4 different rare encounters, a werewolf, a half-orc sorcerer, wood woad, and a specter. Mobs are sparse and scattered though, but with just two real players and a bunch of hires, that may change with a full group.
Quests are actually varied this time around, and are far, far better than Druid's Deep. Each of the three quests we did was in a different location, with a ruined castle, a village courtyard, and a swamp. While nothing is outstanding about them, nothing is bad either, and the XP isn't bad, pretty well on par for the Eveningstar quests. Level is 24, but they were not difficult, and Albus had little problems keeping up with me. It pays to read the dialog and even an item description or two.
Bugs seem rare, with the only one being that we got an optional after we completed the task, but it was able to be completed anyway by redoing it. Also, some Dryads' trees were not there, I think the trees spawned outside the map. We just ignored them, as they're no threat.
All in all, I'd say it's a marked step up from the garbage that was Druid's Deep. Not really a recommended buy, either for fun factor or for must-have gear (at a glance, there are a few nice items, but nothing mandatory), but solid enough that I didn't feel ripped off. Still, it's a far cry from the high quality of House Cannith (crappy XP aside), Harbringer and Reign of Madness, or even the bulk of the Eveningstar/Underdark quests.