The way character damage is handled is by two damage tracks (actually, it's three, the third is specific to magic- and occult-related mishaps and is beyond the scope of what I'm going to talk about here): Stun Points and Wound Points*. The first is the combination of Agility and Vitality attributes, with the full maximum amount for the die size taken as a # of points, the second as a combination of Willpower and Vitality, using the same methodology.
Given this formula, let's see what we have for a collection of various characters:
Stun Points/Wound Points
Weakest PC possible: 8
Average NPC: 12
Average starting PC: 14
Best possible starting PC: 24
Most Powerful PC Possible: 48
So, the most buffed-out character possible has six times the damage capacity of the weakest possible character, not quite four times the damage capacity of the average starting PC and twice the damage capacity of the best possible starting PC.
As a point of comparison, the most damage you could take from a single weapon blow from an NPC is 36 points (d12 weapon with a x3 critical) -- this attack would almost assuredly have associated damage from reoccurring blood loss and non-damage track effects like limbs being severed/mangled; for now, let's just concentrate on pure damage. Such a blow would kill all of the above characters outright except for our theoretical most powerful PC.
So what we have is a system where death can come easy and quick for basically any PC, largely regardless of who they face. On one hand, I like the idea that combat is now far more savage and terrifying -- PCs should think twice about engaging foes toe-to-toe, even if they're just gutter thieves and thus emphasis should be placed on overcoming foes through a large variety of tricks and stratagems -- if you stand a good chance of dying going toe-to-toe, logically more time should be spent coating floors with oil, researching magical weaknesses, etc.
The problem with this is that players in general, and my players specifically, are used to the idea of swatting aside kobolds like flies and this new paradigm just seems to frustrate them because deciding to rough up the smuggler's bodyguards in the alley behind The Tainted Bone, instead of being a show of strength, can easily become a life-or-death struggle with multiple characters suffering near-mortal or permanently disfiguring wounds.
I've been meaning to have a player summit sometime soon, I think this will be one of the questions up for debate: whether they miss the insulating effects of HP and if so, why.
* - Stun Points are like the "abstract combat" aspect of the hit points system, in that they are points that are lost without any real impact on the character, you're essentially "spending them" to not get hit. Wound Points are flesh being cleaved, blood being spilled, etc.