I used to shoot a Zmax.. basically an earlier version of the blackmax.. I shot all the time and was pretty proficient w/ it. I loved the bow. Then I started a family and didn't shoot it much over the winter... and come spring I couldn't shoot nearly as well w/ it. It was very critical and the slightest hand torque would send arrows a few inches off their mark.
So as the others said.. I'd look for a bow w/ a bit more brace height. Also look at other brands besides Mathews.. they are not the end all be all of bows as many believe. But Bowtech on the other hand....