We've had 4 Carrera mountain bikes at work for about 4 years with SRAM X4 triple chain rings. I really don't like the SRAM gears as they have a longer than necessary shift movement (longer than a sweep of my thumb) so I have to twist my hand to change.
My Bianchi hybrid has Shimano Doeore XT gears with triple chaing rings and the change is so sharp and slick it takes a third or quarter of the movemen of the SRAM.
Each of the Carreras has had the rear derailleur adjusted 3 or 4 times.
The Bianchi hasn't had its altered once.
The Tektro brakes on 3 out of 4 Carreras have developed squeals when under hard braking.
The Bianchi hasn't.
With regard to the Voodoo Bizango, if it's hard to find one then maybe it's because:
http://www.mbr.co.uk/reviews/hardtail/voodoo-bizango-29er-review-2013/