I've found that, with a few exceptions (hobgoblin warriors and ogre lords so far), the new PV-applies-before-criticals actually does work quite well. Obviously, though, it still needs a little work.
What about a damage minimum? For instance, any hit that lands always does a minimum of 1 damage, instead of 0? For a player with a hundred hit points, that would be a trifling amount, but it would allow PCs to eventually beat down monsters with high PV.
Or, another idea, perhaps PV affects an exponential percentage of damage, instead of a flat value? So, PV 1 stops 1% of damage, 10 stops, say, 50% of damage, 100 stops 99% of damage... It may not be quite as graceful as the simple damage-PV = hp loss, but this isn't a tabletop game where Players have to calculate this stuff on their own, either.