I built my mtb up from a frame and random pieces so i'm not too good with the new mtbs out there but the fit situation is really a preference thing. It is much easier to decide after you ride some newer bikes in different sizes to see. I am about 180 cm and my bike is a 17 inch but the bike shop guys spec'd me at an 18-18.5inch frame i just prefer the shorter frame for more standover. Only way i found that out though was to go and ride different sizes first.