I just started the Argent Tower level, and so far, it's been very tough but fair. There are some times I feel I got unfairly killed by doing glory kills in a dangerous location, but every encounter seems to be consistently manageable with circle strafing and careful spacing. Kinda shocked at how little heath glory kills will actually give once you're around 70 health. I'm often hurting for ammo, so I need to make a better effort to chainsaw.