I have a Terry Butterfly on my Titus Racer X. Tried a WTB saddle with channel but needed a cutout and more width. I don't see a problem with using a "road" saddle on a mtb, at least for someone like myself who is not a "technical" mountain biker -- I ride fireroads and easy single/double track. I use "mountain" pedals on my roadie too -- whatever works!
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow