The stat system looks and feels good, there isn't any doubt on that. I would even say it works well for average gamers who're new to RPGs. But a veteran can easily see the underlying faults. Yes, health stat impacts the game playing experience the most and becomes the single most important stat. That way I can only be concerned about putting points into health, afford to neglect other stats and yet could have a easy game. I stopped distributing stat points after L-12 or something, yet went on to complete the game twice in hard difficulty settings; this tells me two things, first - the stat system isn't optimized well to make significant impact on game play and secondly - the skill sets are much too powerful(which is great btw) and DOES affect the game much more than the stats. In an ideal RPG scenario, stats and skills should complement each other in a way which makes good use of both to build a character.
There are also skills that effectively compensates for stat points in certain categories, a few points in mana efficiency spares you spending lots of points into your mana stat.
Defensive stats are also disappointing! You need to put in a lot to see any sizable difference. But this because of the leveling system of the game itself. The amount of damage your enemies dish out, as you level up, grows constantly and drastically while your stat points stacks just the same. As a result your defense/resistance never catches up with the amount of damage received. Which makes me wonder whether a more dynamic point distribution system would've proved more efficient, like this: L1-L10 = 4pts. L10-L20 = 5pts. L20 -?? = 6pts. And sure, no caps!
Here is another idea - you get fewer stat points as level up BUT a point squired at higher levels carries much more weight than one you get at a lower level and makes significant difference! That way you've to be more decisive and careful before spending them at a high level when it matters most.
Overall the stat system in DKS is well laid-out and does provide the necessary building blocks, but at the same time it's far from perfect. But I strongly believe Larian shouldn't do a overhaul of things as DKS already has a very robust system(skill/stat/level). All i want them is to fine-tune the quirks while retaining the core elements that made DKS such a great experience! Oh, well, maybe a more logical ending too