So how much harder are the monsters in ladder than in non-ladder? I read the bit in Arreat Summit but it does not really describe the difference. So far my puny ladder zon is a lvl 19 weakling but the monsters don't seem that much worse. My guess is that NM and Hell will be worse.

Nothing like inflicting massive amounts of 12-18 damage on monsters. Yes sir, Hell's minions really fear me...