unless you are hunting elk the mamba is fairly overkill. That said theey are very nice and they have been refined quite a bit since the originals that everyone has shot, and the x2 gives some much needed brace hight. The viper is very comparable to the matthews bows. very smooth, Short ata, great cams. Nibal and darren are great people. give em a call, they will talk bows as long as you want, and they are the first guys to complient bowtech. and some of hte others too.