Congratulations on the new bow. It sound like one sweet shooter. I have yet to hear anyone say anything negative about the new Tribute. That says something when you consider how critical a lot we bowhunters can be.

As for the speed estimate, I would be a little more conservative than Mildot and say somewhere around 270-275 fps with those 450 grain arrows. Some impressive numbers especially when you figure that your setup is putting out between 73 and 76 ft. lbs of KE!