It used to be one of my favorite classes, but now it seems like complete rubbish. The poison glyph is too expensive, too situational (can't use it on undead, and might as well not bother trying on goats, golems or any other magic resist monster) and now he relies on it to get his damage bonus, or he suffers a gimped -20% damage all the time. It was frustrating just trying to beat Den of Danger with him, when I breezed through it with every other class (and what it took was eventually finding an early ENDISWAL glyph so I could use light foot to level up faster).
Speaking of ENDISWAL, is it sad that I'd much rather he start with that instead of APHEELSIK? Light foot is a lot more useful than poisoned blade in most cases. I just convert APHEELSIK immediately in 90% of runs.
I liked it a lot better when the poison glyph was a bonus, and not a requirement. In my experience it's useful at level 1 and then it's trash.