My, Katie Hannon sure is short. Even though the 'speed katies' (where you just deliberately fail the first mission) are gone, it only took 40 minutes for the whole task force. It took 20 minutes to get a full group, but that was probably time well spent -- defeating Mary Macomber ten times in a row isn't that easy... especially the last time when she comes with half a dozen bosses.
Beast Beneath the Mountain is pretty short too. A speedy group managed to get through it in about an hour, it *might* take two if you decide to fight through all the stealthable missions.
Pirates of the Sky takes longer, but you get to fight a giant oil derrick studded with turrets in every imaginable place turrets could be located, so it's worth it.
As far as rewards go, TFs give a 'rare recipe' now -- rare as in 'from a special pool that you can only get by doing task forces'. This means even the somewhat crappy ones go for a couple hundred thousand, most useful ones go for a million or two... Aci's level 40 Decimation Acc/End/Recharge recipe went for eighteen million. Yeah... Aci's not broke anymore.
Anyway, other than task forces, I spent most of the weekend reading through the entire run of Shlock Mercenary. I'd tried to read it a couple times before and gotten turned off by the title character... but while he's annoying and I hate him, he doesn't really figure into the story very much, and the rest of it is neat. It's got a nice 'explore the ramifications of technology' thing going for it.