I own the mamba 7.5 (2010) and compared it against the Viper side-by-side in the shop. I found it a smoother, more forgiving bow, faster too than the viper. Excellent wide range of draw length too if it's required. I shoot 31" and I think both models go beyond that even. Anyway, the (slightly) longer let-off valley and taller brace height of the mamba is what sold me. that and blazing speed of course. The only (very small) detractor is that it is a Canadian company... ie on hunting and range trips you'll need a set of imperial AND metric allen keys... hardly significant.. but it is something to remember. At any rate a 33" axel to axel length and HUGE forgiveness add up to a killer bow. After 5 years away from shooting and within only about 150 shots I'm easily getting 5" groupings at 50 yards. so it is accurate, fast, smooth, forgiving. all round great bow. Nibal (company founder/owner) is very friendly and helpful too.