I shoot both.
Crossbows cannot be tuned like vertical bows can so sometimes it is necessary to make the move to expandables if you are not getting good accuracy with fixed heads. You can often tighten the fixed head groups by going with spine indexed arrows or playing with front of center balance and arrow length. If you are getting good accuracy with fixed heads, there is no great reason to try mechanicals.
A fixed head and mechanical of the same cutting diameter cause the same damage.
You can generally get a bigger cutting diameter with mechanicals without potentially creating accuracy issues. The little extra cut diameter is a slight advantage if your shot is a touch off. The extra 1/2 inch may be the difference between a flesh wound and a kill shot. I use bigger mechanicals when I am turkey hunting cause the kill zone is so small.
I shot a black bear with a expandable a month ago but I am switching over to Slick Trick fixed heads for an upcoming wild hog hunt just for a little added insurance on hogs.
Bottom line is if your primary interest is deer, and you are currently getting good flight from fixed heads, there is no great advantage to switching to mechanicals in crossbows, IMO.
I support all hunters, regardless of weapon or technique!
Last edited by dpms; 07-18-2018 at 02:36 PM.