I currently shoot a Q2 and I would recommend that you take an old arrow and make a ruler out of it with felt pen. Start from the pocket in the nock of the arrow. Have a friend with you and have him tell you the length of measurement at about 1/2 to 3/4 in in front of the arrowrest. This should be about the center of the riser to just a bit behind center. The riser was designed for this and has plenty of clearence for your broadheads. This should get you the most out of your Mathews. I have a 30 inch draw length and shoot aluminum with uni's. The arrows are just shy of 30 inches from nock pocket to end.
A note of caution with this set-up though. It is HIGHLY recommended that your rest have a tray or guard in the event the arrow falls off the rest at full draw and cuts the crap out of your hand.