ITs essentially a poorly designed single pivot with a really high leverage ratio. This leaves the shock in a position to blow out easier than most designs. It also was known to have many many issues with the rear linkage loosening and generally breaking. This is 2003 and before. In 2004 they remade the bike and called it a RMX which fixed most of the problems with the linkage plates and bushings. In short...wayyyyyyyyyyyyyy overpriced for a bike with a good rep (wade simmons and every 12 year old in BC) in Canada but in reality the bike was a pile of poo...
At that weight, the shivers will be sweet.
With those frames the bikes will weight quite a bit. The advantage of a HT is beyond weight. In all cases...the last bike I would recommend is the rm7. Definately NOT suited for what you described.