I'm curious to know how pre-packaged adventure paths have worked out for anyone who has tried running them, specifically the Paizo ones.

In my experience, my campaigns wander off script fairly regularly. I tried running the Shackled City one from Dungeon, but ended up creating my own campaign after the first (quite enjoyable) adventure. The stuff that interested my players didn't match up with the second adventure in the series, so out the window it went.

I've looked at Rise of the Runelords, but I felt like the work needed to properly learn and prepare it was about equal to the effort of rolling my own.

Am I off base here? Is Runelords a bad one to look at? Are these things easier in play to handle than it looks?

I've run Rise of the Runelords and played through Curse of the Crimson throne.  I started playing Second Darkness but didn't get very far.  I've tried to run Shackled City as a pbp but it hasn't worked out.  I've looted parts of Savage Tide for a pirate themed campaign.

As a player, Crimson Throne was awesome.  We felt attached to the city, and it really felt fleshed out.  Definitely felt like a good sandbox.

The players enjoyed Rise of the Runelords.  At high levels, the wizard was pretty dominant (not really his fault).  But plot and pacing worked out well.  I did make some changes - mostly really fleshing out the starting town.  I think the first half tended to be better - it felt like a rush to the end.  I also added or expanded some things to slow down the rapid pace of advancement.

That's my main advice to anyone running one - use it as a sketch, but add more content.  Give the players more opportunity to enjoy each level.  If an adventure assumes gaining 3 levels during that one adventure, change is warranted.

Hmm...

I've run Shackled City in the past - which went... mostly well but we got tired of it before we got to the end... and I'm currently running the Carrion Crown one over roll20.com, although we're only on the first book.

They're okay?  The problem with the Carrion Crown is that in the beginning it kind of assumes that PCs are going to hang out in town doing not much at all for a week or two while a perfectly good haunted prison is lurking on the outskirts of town... how that got through playtesting I don't know.  As such, they're already upsetting applecarts that the text assumes will roll downhill and hit town.

On the other hand, the haunted prison is a fair bit of fun.