No WAY would I want a Brooks on a mountain bike! You have to be able to get off the back of the bike which means being able to get behind the saddle so its best to have a narrower saddle. You also need a longer saddle so you can sit far forward for steep climbs. And the hardware hanging all over a Brooks would put significant gouges in me or my shorts. Ow. Not that they aren't fine for the road.
I use a WTB Stealth. Is that right, TrekHawk? They keep changing the saddle names. Yellow uses a WTB rocket (I think). Many WTB saddles have slight downturned noses which help reduce chamois suck.
I wouldn't recommend the Speed V as it's so short.
Frends know gud humors when dey is hear it. ~ Da Crockydiles of ZZE.