RotR ACG was our first Pathfinder experience, and it was great. We bought the base game, and all of the adventure packs and had a wonderful time with them. We still do!
The problem was (and remember we're new to the franchise) if you ask anyone in the group the best part of the game, none of the responses would be that we were pumped to see how the story resolved, which is a shame as it's obviously a little brother to the RPG. The story just didn't punch through via the card game format. After playing for a month or so I ended up reading up on the full RPG storyline to help flesh it out a little. It actually made the game even more enjoyable for me (seeing how it was implemented in card format) but I am sure I am in the minority.
Instead, the group fondly remembers grinding for loot, levelling up, how awesome the holy candle is, and that bastard villain. No real idea why he's a bastard, but we got him and that was cool. It basically became (again, for a group of newcomers) Diablo in card game form - and we loved it.
So when the new game seemed (almost) the same thing focused on a new plot, no-one was excited as the plot wasn't what excited us in the first one. It was the cool "holy sh*t we found the villain with one card left in the blessings deck" moments, or making your mates promise to make you cups of tea for a month in exchange for some awesome loot you found (which I can't use anyway, but that's not the point)...
We would love an addendum to RotR complimenting our existing box of awesome with new shiny loot, villains and monsters. New smaller, simpler (storywise) stand alone side quests that perhaps even help flesh out Sandpoint for Pathfinder newbies, as I'm sure for many this is their first experience with the franchise. Finally, a rating system - story packs for new parties (equivalent to say adventure pack 2), for mid strength (adventure pack 4 equivalent), and a new epic level for people that just love their maxed out characters now gathering dust (Adventure pack 6++).
Either that, or a really different take on the RPG -> card format. Otherwise we are super happy with what we have currently!
I hope I haven't prattled on for too long. We really do love the game!