Nobles are, for the most part, a liability. The only nobles that are even slightly helpful are the ones that let you see what things are worth, and the one that lets you chasm and melt things directly. Everyone else is just... there... and if they die, you lose immigration waves. The sherrif and hammerer are equally useless. 95% of the time, they imprison (AND OR BEAT TO NEAR DEATH) dwarves for milk-spill accidents that you otherwise would have dismissed or not even noticed. Not once in my 40 combined game years of governing fortresses have i EVER seen a dwarf recover back to normal after being hammered or hit from the sherrif.
And the 5% of the time they arrest someone dangerous, you probably could have brought them down your self with your personal army, and faster too since you can directly choose which of your dwarves would do it.
Even when they do arrest a dangerous dwarf, it doesn't matter, because if they've gotten so unhappy they are a danger to the community then imprisoning them is only making it worse (difficult for dwarves to sleep on rough stone, dwarves late on delivering food and water, depression from imprisonment).
All in all, you might as well declare the "Golden Age" of dwarves -over- when you see that first, purple happy face pop up on the far west side of your kingdom.....
[ March 26, 2007: Message edited by: ColonelTEE3 ]