Check out this thread:
http://warhammer.org.uk/PhP/viewtopic.php?t=36307&start=0
Overall it appears that they hit pretty hard, but are fragile, and the army tends to be pretty small in terms of model (and often unit) count.
Swordmasters are sexy, but relying on dice/kills to get
CR can be dangerous, as one bad round of rolls can mean a lost unit. While Lions are becoming more popular, as their Stubborn makes them less subject to this weakness, they still hit very hard, and they have better resistance to shooting. Some people are also finding that Phoenix Guard can make a heck of an anvil, though its pricey.
Ranked infantry units usually have some trouble trying to dictate the terms of engagement, but HE break the usual dynamic by not caring about who gets the charge (except against chariots). I think this is something players are still learning to use. It should be particularly powerful if you can push an infantry unit into an enemy units face to force them to charge, while simultaneously moving a cavalry unit into flanking position to slam them the turn after they charge you.
I think
BSBs are critical for this army, to keep your expensive units from running. The fact that theyre allowed to take a great weapon and/or shield, means they can also be significantly more killy/durable than other armies
BSBs. Which is sweet.
A lot of players are taking minimal Core unita which to me is a problem. Core (at least in my personal conception) should represent a significant portion of an army, and give it bulk. Some people are reporting success with spears and/or archers, however, which is a nice sign.