I’ve always found obsidian to be a challenge.  Yes, it knaps easily, but I think that’s also the problem.  And, I’m just not much on glass.  It’s messy.  There is a reason why I’ve heard it referred to as “obs#*tian” in some knapping pits.  But, done right, they are sharp points, no doubt.
Keokuk can get funny for me, also.  I dunno...kinda chalky or something.  Just doesn’t play nice for me.
That’s just my perspective, though.  Different strokes...
Dacite is like a slightly glassier G’town.  G’town was what I really cut my teeth on.  A little went a long way and it has that sweet spot, right in the middle, for characteristics.  Only problem with it is it only comes in one color!