Inspired by your post, I gave it a test.. T6 Infestation in the medical factory, full stealth setup. For sure it's a lot rougher now, as in some zeds will actually notice you and likely get a few hits in.
A lot of zeds died without waking up, most others didn't wake up anyone else; I think I woke up more with the glancing blows.
Some trigger rooms triggered partially, most didn't at all. (key-triggers of course triggered fully)
If a zed started wandering, after a few tries I didn't have the patience to wait for a chance at "new" sneak damage - they die faster just spamming machete at face...
On the upside, it's now "playable"; you'll actually be in some danger and will have to do _something_.
On the downside, the overall feeling of it now is .. back to punishing randomness. You can't really predict what will trigger and when, and how bad it'll be. The straight up combat route (even as Agi build) might be preferable more often than not.